Methods for treating headache

ABSTRACT

A headache can be treated effectively by administration of a botulinum toxin to a patient at specific muscles using specific doses.

CROSS REFERENCE

This application is a continuation of U.S. patent application Ser. No.12/256,655, filed Oct. 23, 2008, which is a continuation of U.S. patentapplication Ser. No. 11/329,598, filed Jan. 11, 2006, now U.S. Pat. No.7,704,511, which is a continuation of U.S. patent application Ser. No.11/319,880, filed Dec. 28, 2005, now abandoned, which is a continuationof U.S. patent application Ser. No. 11/039,506, filed Jan. 18, 2005, nowabandoned, which is a continuation-in-part of U.S. patent applicationSer. No. 10/789,180, filed Feb. 26, 2004, the entire content of eachapplication is incorporated herein by reference.

BACKGROUND

The present invention relates to methods for treating pain. Inparticular, the present invention relates to use of a botulinum toxin totreat and prevent headaches and to treat an acute pain alleviationmedication disorder. The present invention also includes improvedmethods for treating headaches by using a triptan and a botulinum toxinto treat a headache, and methods for increasing the effectiveness of atriptan to treat a headache, such as a migraine headache.

Many, if not most ailments of the body cause pain. Generally pain isexperienced when the free nerve endings which constitute the painreceptors in the skin as well as in certain internal tissues aresubjected to mechanical, thermal, chemical or other noxious stimuli. Thepain receptors can transmit signals along afferent neurons into thecentral nervous system and thence to the brain.

The causes of pain can include inflammation, injury, disease, musclespasm and the onset of a neuropathic event or syndrome. Ineffectivelytreated pain can be devastating to the person experiencing it bylimiting function, reducing mobility, complicating sleep, anddramatically interfering with the quality of life.

A muscle spasm can led to stimulation of mechanosensitive pain receptorsthereby causing a sensation of pain. Thus, pain can arise from or be dueto a muscle spasm. Additionally, the spasm can indirectly stimulate thepain receptors by compressing onto blood vessels, causing ischemia inthe tissue, which in turn releases pain inducing substances thatstimulate pain receptors to cause pain sensations. Furthermore, a musclespasm can cause a localized pH reduction which can be perceived as orwhich can engender pain signals. Hence, pain can be a secondary effectof a muscle spasm or muscle hypertonicity.

Inflammatory pain can occur when tissue is damaged, as can result fromsurgery or due to an adverse physical, chemical or thermal event or toinfection by a biologic agent. When a tissue is damaged, a host ofendogenous pain inducing substances, for example bradykinin andhistamine can be released from the injured tissue. The pain inducingsubstances can bind to receptors on the sensory nerve terminals andthereby initiate afferent pain signals.

Additionally, pain inducing substances can be released from nociceptiveafferent terminals, and neuropeptides released from sensory terminalscan accentuate an inflammatory response. Thus, during inflammation therecan be a sprouting of peptidergic peripheral fibers and an increasedcontent of peptide, with many fibers showing a coexistence of substanceP (SP) and calcitonin gene related peptide (CGRP). Substance P caninduce contraction of endothelia cells, which in turn causes plasmaextravasation to allow other substances (bradykinin, ATP, histamine) togain access to the site of injury and the afferent nerve terminals.Substance P release by the sensory nerve terminal can also degranulatemast cell. This process has been considered to be an important factor inneurogenic inflammation due to the release of inflammatory mediatorssuch as histamine and serotonin and the release of proteolytic enzymeswhich catalyze the production of bradykinin. CGRP apparently does notproduce plasma extravasation but is a powerful vasodilator and also actsynergistically with SP and other inflammatory mediators to enhanceplasma extravasation. All the above listed inflammatory mediators caneither sensitize nociceptors or produce pain.

After activation of the primary sensory afferent neurons the next stepin the transduction of sensory signals can be activation of projectionneurons, which carry the signal, via the spinothalamic tract, to higherparts of the central nervous system such as the thalamic nuclei. Thecell bodies of these neurons (other than those related to the cranialnerves) are located in the dorsal horn of the spinal cord. Here also onecan find the synapses between the primary afferents and the projectionneurons. The dorsal horn is organized into a series of laminae that arestacked, with lamina I being most dorsal followed by lamina II, etc. Thedifferent classes of primary afferents make synapses in differentlaminae. For cutaneous primary afferents, C-fibers make synapses inlaminae I and II, A delta-fibers in laminae I, II, and V, and Abeta-fibers in laminae III, IV, and V. Deeper laminae (V-VII, X) arethought to be involved in the sensory pathways arriving from deepertissues such as muscles and the viscera.

The predominant neurotransmitters at the synapses between primaryafferent neurons and projection neurons are substance P, glutamate, CGRPand neuropeptide Y. The efficiency of transmission of these synapses canbe altered via descending pathways and by local interneurons in thespinal cord. These modulatory neurons can release a number of mediatorsthat are either inhibitory (e.g. opioid peptides, glycine) or excitatory(e.g. nitric oxide, cholecystokinin), to provide a mechanism forenhancing or reducing awareness of sensations.

Although inflammatory pain is generally reversible and subsides when theinjured tissue has been repaired or the pain inducing stimulus removed,present methods for treating inflammatory pain have many drawbacks anddeficiencies. Thus, the typical oral, parenteral or topicaladministration of an analgesic drug to treat the symptoms of pain or of,for example, an antibiotic to treat inflammatory pain causation factorscan result in widespread systemic distribution of the drug andundesirable side effects. Additionally, current therapy for inflammatorypain suffers from short drug efficacy durations which necessitatefrequent drug re-administration with possible resulting drug resistance,antibody development and/or drug dependence and addiction, all of whichare unsatisfactory. Furthermore, frequent drug administration increasesthe expense of the regimen to the patient and can require the patient toremember to adhere to a dosing schedule.

Examples of treatments for inflammation and muscle pain includenon-steroidal anti-inflammatory drugs (NSAIDS), including aspirin andibuprofen; and opioids, such as morphine.

NSAIDs alleviate pain by inhibiting the production of prostaglandinsreleased by damaged tissues. Prostaglandins have been shown to beperipheral mediators of pain and inflammation, as in arthritic diseases,and a reduction in their concentration provides relief to patients. Ithas been suggested that prostaglandins are involved in the mediation ofpain in the spinal cord and the brain, which may explain the analgesiceffects of NSAIDS in some pain states that do not involve inflammationor peripheral tissue damage. However, prostaglandins are only one ofseveral mediators of pain. As such, NSAIDs have a ceiling of activityabove which increasing doses do not give more pain relief. Furthermore,they have side effects that limit their usefulness. For example, NSAIDscan cause irritation of the gastro-intestinal tract and prolonged usemay lead to the development of extensive ulceration of the gut. This isparticularly true in elderly patients who frequently use NSAIDs fortheir arthritis conditions.

The therapeutic actions of opioids are in the spinal cord. Opioidsinhibit the efficiency of neurotransmission between the primary sensoryafferents (principally C-fibers) and the projection neurons. Theyachieve this by causing a prolonged hyperpolarization of both elementsof these synapses. The use of opioids is effective in alleviating mosttypes of acute pain and chronic malignant pain. There are, however, anumber of chronic malignant pain conditions which are partly orcompletely refractory to opioid analgesia, particularly those whichinvolve nerve compression, e.g. by tumor formation. Unfortunatelyopioids also have unwanted side-effects including: (1) depression of therespiratory system, (2) constipation, and (3) psychoactive effectsincluding sedation and euphoria. These side effects occur at dosessimilar to those that produce analgesia and therefore limit the dosesthat can be given to patients. Additionally, opioids such as morphineand heroin are well-known drugs of abuse that lead to physicaldependence, which also involves the development of tolerance. With thedevelopment of tolerance, the dose of a drug required to produce thesame analgesic effect increases with time. This may lead to a conditionin which the doses required to alleviate the pain are life-threateningdue to previously mentioned side-effects.

Although pain arising from inflammation and muscle spasm can beinitiated by mechanical or chemical stimulation of the primary sensoryneuron free terminal, neuropathic pain does not require an initialstimulus to the peripheral, free nerve terminal. Neuropathic pain is apersistent or chronic pain syndrome that can result from damage to thenervous system, the peripheral nerves, the dorsal root ganglion, dorsalroot, or to the central nervous system.

Neuropathic pain syndromes include allodynia, various neuralgias such aspost herpetic neuralgia and trigeminal neuralgia, phantom pain, andcomplex regional pain syndromes, such as reflex sympathetic dystrophyand causalgia. Causalgia is often characterized by spontaneous burningpain combined with hyperalgesia and allodynia.

Unfortunately, there is no existing method for adequately, predictablyand specifically treating established neuropathic pain (Woolf C. et al.,Neuropathic Pain: Aetiology, Symptoms, Mechanisms, and Management,Lancet 1999; 353: 1959-64) as present treatment methods for neuropathicpain consists of merely trying to help the patient cope throughpsychological or occupational therapy, rather than by reducing oreliminating the pain experienced.

For example, current methods to treat neuropathic pain includeadministration of local anesthetic blocks targeted to trigger points,peripheral nerves, plexi, dorsal roots, and to the sympathetic nervoussystem. However, these treatments have only short-lived antinociceptiveeffects. Additionally, longer lasting analgesic treatment methods, suchas blocks by phenol injection or cryotherapy raise a considerable riskof irreversible functional impairment. Furthermore, chronic epidural orintrathecal (collectively “intraspinal”) administration of drugs such asclonidine, steroids, opioids or midazolam have significant side effectsand questionable efficacy.

Headache

A headache is a pain in the head, such as in the scalp, face, foreheador neck. A headache can be a primary headache or a secondary headache. Aprimary headache is a headache which is not caused by another condition.Contrarily, a secondary headache is due to a disease or medicalcondition, such as an illness, infection, injury, stroke or otherabnormality. Thus, with a secondary headache there is an underlyingdisorder that produces the headache as a symptom of that underlyingdisorder. Tension headache is the most common type of primary headacheand tension headaches account for about 90% of all headaches. A tensionheadache is often experienced in the forehead, in the back of the headand neck, or in both regions. It has been described as a tight feeling,as if the head were in a vise. Soreness in the shoulders or neck iscommon. Nausea is uncommon with a tension headache.

Migraine headaches are recurrent headaches that may be unilateral orbilateral. Migraine headaches may occur with or without a prodrome. Theaura of a migraine may consist of neurologic symptoms, such asdizziness, tinnitus, scotomas, photophobia, or visual scintillations(eg, bright zigzag lines). Migraines without aura are the most common,accounting for more than 80% of all migraines.

An estimated 10-20% of the population suffers from migraine headaches.An estimated 6% of men and 15-17% of women in the United States havemigraine. Migraines most commonly are found in women, with a 3:1female-to-male ratio.

About 2% of all headaches are secondary headaches. For example, acervicogenic headache is a headache which is due to a neck problem, suchas an abnormality of neck muscles, which can result from prolonged poorposture, arthritis, injuries of the upper spine, or from a cervicalspine disorder. Sinus headache is another type of secondary headache. Asinus headache can be caused by inflammation and/or infection in theparanasal sinuses.

Medication Overuse Headache Disorder

Daily or near-daily headache can affect up to 5% of some populations,and it is believed that chronic overuse of headache drugs may accountfor half of this phenomenon. All simple analgesics, and probablynon-steroidal anti-inflammatory drugs, ergotamine, and triptans, areimplicated. Triptans are a family of tryptamine drugs used in thetreatment of headache. Triptans act by binding to serotonin 5-HT_(1B)and 5-HT_(1D) receptors in cranial blood vessels (causing theirconstriction) and subsequent inhibition of pro-inflammatory neuropeptiderelease. Thus, triptans are 5HT(1B/1 D) receptor agonists and arecommonly prescribed for migraine headache treatment. Sumatriptan(Imitrex®, Imigran®), zolmitriptan (Zomig®), naratriptan (Amerge®,Naramie), rizatriptan (Maxale), almotriptan (Axere), frovatriptan(Frova®), and eletriptan (Relpax®) are triptan drugs.

Medication overuse headache affects more women than men (on a ratio of5:1) and some children. The regular intake of three or more analgesictablets daily or narcotics or ergotamine on more than two days a week tocontrol or alleviate a headache has been suggested as a medicationoveruse headache definition. A common and probably key factor inmedication overuse headache is pre-emptive use of drugs, in anticipationof rather than for a headache. Medication overuse headache usually doesnot develop when analgesics are regularly taken for another indication,such as chronic backache or rheumatic disease, that is the headache mustbe present to begin with.

A presumptive diagnosis of medication overuse headache is based onsymptoms and a detailed history of drug use, including over the counterdrugs. Many patients with medication overuse headache disorder use largequantities of drug: 35 doses a week on average in one study, and sixdifferent agents. Sooner or later, such patients seek prescriptions for“something stronger,” bringing them to the general practitioner'sattention. However, medication overuse headache is typically confirmedonly when symptoms improve after drugs are withdrawn. The headache isoppressive, present, and often at its worst on awakening in the morning.It can be increased after physical exertion. Associated nausea andvomiting are rarely pronounced. A typical history begins with episodicheadache up to years earlier (more commonly migraine than tension-typeheadache), treated with an analgesic or other acute medication. Overtime, headache episodes become more frequent, as does drug intake, untilboth are daily. In the end stage, which not all patients reach, headachepersists all day, fluctuating with medication use repeated every fewhours. This evolution occurs over a few weeks or much longer, dependinglargely but not solely on the medication taken.

The International Headache Society defines medication overuse headache(MOH) as a chronic headache (headache frequency >15 days per month)after the intake of analgesics or ergots (more than 15 times per monthfor at least 3 months), which disappears after withdrawal therapy. Ithas been described as a self-sustaining, rhythmic, headache medicationcycle characterized by daily or near daily headache and irresistible andpredictable use of immediate relief medications. Evidence supporting theexistence of MOH is widely published in the medical literature.

The pathogenesis of MOH has not been fully elucidated. Some evidencesuggests that up regulation of serotonin receptors and subsequentreduction in serotonin levels, which normalize upon cessation of chronicanalgesic use, may play a role. The following have also been implicatedin the development of MOH: endorphin suppression, central opioidreceptor impairment, impaired suppression or downregulation of analready partly suppressed or abnormal antinociceptive system,alterations in density and function of postsynaptic neuronal receptors,and activation of nociceptive “on-cells” in the ventral medulla thatfacilitate nociceptive reflex responses. A common presentation is apatient with a history of episodic migraine with or without aura, whocomplains of increased headache frequency and the development ofinterparoxysmal tension-type headache, that eventually transforms into adaily or near-daily headache lasting for prolonged periods. Patients mayalternate between migraine-type and tension-type headaches during thisperiod. Behavioral and psychiatric comorbidities may also be present andare complicating factors. It is common for patients to underestimatetheir use of analgesics and to use multiple types of agentsconcomitantly. Initially, pain relief provides negative reinforcement,and in some cases changes in mood incurred from barbiturate andcaffeine-containing analgesics, may provide positive reinforcement,resulting in excessive use. Tolerance, characterized by increasingconsumption without regard to potential adverse outcomes, and withdrawalsymptoms upon abrupt discontinuation, often ensue and result inincreased headache frequency and severity with a decrease in analgesicefficacy. Concomitant preventive medications are relatively ineffective,while the patient is using excessive amounts of abortive agents andcomplete discontinuation of headache medication is the treatment ofchoice. Detoxification is usually conducted slowly over as many as 8 to12 weeks and in the most severe cases, may warrant hospitalization.

Medication overuse to treat headache (“MOH”) has been recentlyrecognized as a unique disorder diagnosis of the InternationalClassification of Headache Disorders, 2^(nd) edition, published insupplement 1, Cephalalgia 2004: volume 24, pages 94-95, wherein,significantly, it is stated that patients with a MOH disorder rarelyrespond to other preventive medications while they are overusing theiracute pain medications.

Botulinum Toxin

The genus Clostridium has more than one hundred and twenty sevenspecies, grouped according to their morphology and functions. Theanaerobic, gram positive bacterium Clostridium botulinum produces apotent polypeptide neurotoxin, botulinum toxin, which causes aneuroparalytic illness in humans and animals referred to as botulism.The spores of Clostridium botulinum are found in soil and can grow inimproperly sterilized and sealed food containers of home basedcanneries, which are the cause of many of the cases of botulism. Theeffects of botulism typically appear 18 to 36 hours after eating thefoodstuffs infected with a Clostridium botulinum culture or spores. Thebotulinum toxin can apparently pass unattenuated through the lining ofthe gut and attack peripheral motor neurons. Symptoms of botulinum toxinintoxication can progress from difficulty walking, swallowing, andspeaking to paralysis of the respiratory muscles and death.

Botulinum toxin type A is the most lethal natural biological agent knownto man. About 50 picograms of a commercially available botulinum toxintype A (purified neurotoxin complex)¹ is a LD₅₀ in mice (i.e. 1 unit).One unit of BOTOX® contains about 50 picograms (about 56 attomoles) ofbotulinum toxin type A complex. Interestingly, on a molar basis,botulinum toxin type A is about 1.8 billion times more lethal thandiphtheria, about 600 million times more lethal than sodium cyanide,about 30 million times more lethal than cobra toxin and about 12 milliontimes more lethal than cholera. Singh, Critical Aspects of BacterialProtein Toxins, pages 63-84 (chapter 4) of Natural Toxins II, edited byB. R. Singh et al., Plenum Press, New York (1976) (where the stated LD₅₀of botulinum toxin type A of 0.3 ng equals 1 U is corrected for the factthat about 0.05 ng of BOTOX® equals 1 unit). One unit (U) of botulinumtoxin is defined as the LD₅₀ upon intraperitoneal injection into femaleSwiss Webster mice weighing 18 to 20 grams each. ¹ Available fromAllergan, Inc., of Irvine, Calif. under the tradename BOTOX® in 100 unitvials)

Seven generally immunologically distinct botulinum neurotoxins have beencharacterized, these being respectively botulinum neurotoxin serotypesA, B, C₁, D, E, F and G each of which is distinguished by neutralizationwith type-specific antibodies. The different serotypes of botulinumtoxin vary in the animal species that they affect and in the severityand duration of the paralysis they evoke. For example, it has beendetermined that botulinum toxin type A is 500 times more potent, asmeasured by the rate of paralysis produced in the rat, than is botulinumtoxin type B. Additionally, botulinum toxin type B has been determinedto be non-toxic in primates at a dose of 480 U/kg which is about 12times the primate LD₅₀ for botulinum toxin type A. Moyer E et al.,Botulinum Toxin Type B: Experimental and Clinical Experience, beingchapter 6, pages 71-85 of “Therapy With Botulinum Toxin”, edited byJankovic, J. et al. (1994), Marcel Dekker, Inc. Botulinum toxinapparently binds with high affinity to cholinergic motor neurons, istranslocated into the neuron and blocks the release of acetylcholine.Additional uptake can take place through low affinity receptors, as wellas by phagocytosis and pinocytosis.

Regardless of serotype, the molecular mechanism of toxin intoxicationappears to be similar and to involve at least three steps or stages. Inthe first step of the process, the toxin binds to the presynapticmembrane of the target neuron through a specific interaction between theheavy chain, H chain, and a cell surface receptor; the receptor isthought to be different for each type of botulinum toxin and for tetanustoxin. The carboxyl end segment of the H chain, H_(C), appears to beimportant for targeting of the toxin to the cell surface.

In the second step, the toxin crosses the plasma membrane of thepoisoned cell. The toxin is first engulfed by the cell throughreceptor-mediated endocytosis, and an endosome containing the toxin isformed. The toxin then escapes the endosome into the cytoplasm of thecell. This step is thought to be mediated by the amino end segment ofthe H chain, H_(N), which triggers a conformational change of the toxinin response to a pH of about 5.5 or lower. Endosomes are known topossess a proton pump which decreases intra-endosomal pH. Theconformational shift exposes hydrophobic residues in the toxin, whichpermits the toxin to embed itself in the endosomal membrane. The toxin(or at a minimum the light chain) then translocates through theendosomal membrane into the cytoplasm.

The last step of the mechanism of botulinum toxin activity appears toinvolve reduction of the disulfide bond joining the heavy chain, Hchain, and the light chain, L chain. The entire toxic activity ofbotulinum and tetanus toxins is contained in the L chain of theholotoxin; the L chain is a zinc (Zn++) endopeptidase which selectivelycleaves proteins essential for recognition and docking ofneurotransmitter-containing vesicles with the cytoplasmic surface of theplasma membrane, and fusion of the vesicles with the plasma membrane.Tetanus neurotoxin, botulinum toxin types B, D, F, and G causedegradation of synaptobrevin (also called vesicle-associated membraneprotein (VAMP)), a synaptosomal membrane protein. Most of the VAMPpresent at the cytoplasmic surface of the synaptic vesicle is removed asa result of any one of these cleavage events. Botulinum toxin serotype Aand E cleave SNAP-25. Botulinum toxin serotype C₁ was originally thoughtto cleave syntaxin, but was found to cleave syntaxin and SNAP-25. Eachof the botulinum toxins specifically cleaves a different bond, exceptbotulinum toxin type B (and tetanus toxin) which cleave the same bond.Each of these cleavages block the process of vesicle-membrane docking,thereby preventing exocytosis of vesicle content.

Botulinum toxins have been used in clinical settings for the treatmentof neuromuscular disorders characterized by hyperactive skeletal muscles(i.e. motor disorders). In 1989 a botulinum toxin type A complex hasbeen approved by the U.S. Food and Drug Administration for the treatmentof blepharospasm, strabismus and hemifacial spasm. Subsequently, abotulinum toxin type A was also approved by the FDA for the treatment ofcervical dystonia and for the treatment of glabellar lines, and abotulinum toxin type B was approved for the treatment of cervicaldystonia. Non-type A botulinum toxin serotypes apparently have a lowerpotency and/or a shorter duration of activity as compared to botulinumtoxin type A. Clinical effects of peripheral intramuscular botulinumtoxin type A are usually seen within one week of injection. The typicalduration of symptomatic relief from a single intramuscular injection ofbotulinum toxin type A averages about three months, althoughsignificantly longer periods of therapeutic activity have been reported.

Although all the botulinum toxins serotypes apparently inhibit releaseof the neurotransmitter acetylcholine at the neuromuscular junction,they do so by affecting different neurosecretory proteins and/orcleaving these proteins at different sites. For example, botulinum typesA and E both cleave the 25 kiloDalton (kD) synaptosomal associatedprotein (SNAP-25), but they target different amino acid sequences withinthis protein. Botulinum toxin types B, D, F and G act onvesicle-associated protein (VAMP, also called synaptobrevin), with eachserotype cleaving the protein at a different site. Finally, botulinumtoxin type C₁ has been shown to cleave both syntaxin and SNAP-25. Thesedifferences in mechanism of action may affect the relative potencyand/or duration of action of the various botulinum toxin serotypes.Apparently, a substrate for a botulinum toxin can be found in a varietyof different cell types. See e.g. Biochem J 1; 339 (pt 1):159-65:1999,and Mov Disord, 10(3):376:1995 (pancreatic islet B cells contains atleast SNAP-25 and synaptobrevin).

The molecular weight of the botulinum toxin protein molecule, for allseven of the known botulinum toxin serotypes, is about 150 kD.Interestingly, the botulinum toxins are released by Clostridialbacterium as complexes comprising the 150 kD botulinum toxin proteinmolecule along with associated non-toxin proteins. Thus, the botulinumtoxin type A complex can be produced by Clostridial bacterium as 900 kD,500 kD and 300 kD forms. Botulinum toxin types B and C₁ is apparentlyproduced as only a 700 kD or 500 kD complex. Botulinum toxin type D isproduced as both 300 kD and 500 kD complexes. Finally, botulinum toxintypes E and F are produced as only approximately 300 kD complexes. Thecomplexes (i.e. molecular weight greater than about 150 kD) are believedto contain a non-toxin hemagglutinin protein and a non-toxin andnon-toxic nonhemagglutinin protein. These two non-toxin proteins (whichalong with the botulinum toxin molecule comprise the relevant neurotoxincomplex) may act to provide stability against denaturation to thebotulinum toxin molecule and protection against digestive acids whentoxin is ingested. Additionally, it is possible that the larger (greaterthan about 150 kD molecular weight) botulinum toxin complexes may resultin a slower rate of diffusion of the botulinum toxin away from a site ofintramuscular injection of a botulinum toxin complex.

In vitro studies have indicated that botulinum toxin inhibits potassiumcation induced release of both acetylcholine and norepinephrine fromprimary cell cultures of brainstem tissue. Additionally, it has beenreported that botulinum toxin inhibits the evoked release of bothglycine and glutamate in primary cultures of spinal cord neurons andthat in brain synaptosome preparations botulinum toxin inhibits therelease of each of the neurotransmitters acetylcholine, dopamine,norepinephrine (Habermann E., et al., Tetanus Toxin and Botulinum A andC Neurotoxins Inhibit Noradrenaline Release From Cultured Mouse Brain, JNeurochem 51(2); 522-527:1988) CGRP, substance P and glutamate(Sanchez-Prieto, J., et al., Botulinum Toxin A Blocks GlutamateExocytosis From Guinea Pig Cerebral Cortical Synaptosomes, Eur J.Biochem 165; 675-681:1897. Thus, when adequate concentrations are used,stimulus-evoked release of most neurotransmitters is blocked bybotulinum toxin. See e.g. Pearce, L. B., Pharmacologic Characterizationof Botulinum Toxin For Basic Science and Medicine, Toxicon 35(9);1373-1412 at 1393; Bigalke H., et al., Botulinum A Neurotoxin InhibitsNon-Cholinergic Synaptic Transmission in Mouse Spinal Cord Neurons inCulture, Brain Research 360; 318-324:1985; Habermann E., Inhibition byTetanus and Botulinum A Toxin of the release of [ ³ H]Noradrenaline and[ ³ H]GABA From Rat Brain Homogenate, Experientia 44; 224-226:1988,Bigalke H., et al., Tetanus Toxin and Botulinum A Toxin Inhibit Releaseand Uptake of Various Transmitters, as Studied with ParticulatePreparations From Rat Brain and Spinal Cord, Naunyn-Schmiedeberg's ArchPharmacol 316; 244-251:1981, and; Jankovic J. et al., Therapy WithBotulinum Toxin, Marcel Dekker, Inc., (1994), page 5.

Botulinum toxin type A can be obtained by establishing and growingcultures of Clostridium botulinum in a fermenter and then harvesting andpurifying the fermented mixture in accordance with known procedures. Allthe botulinum toxin serotypes are initially synthesized as inactivesingle chain proteins which must be cleaved or nicked by proteases tobecome neuroactive. The bacterial strains that make botulinum toxinserotypes A and G possess endogenous proteases and serotypes A and G cantherefore be recovered from bacterial cultures in predominantly theiractive form. In contrast, botulinum toxin serotypes C₁, D and E aresynthesized by nonproteolytic strains and are therefore typicallyunactivated when recovered from culture. Serotypes B and F are producedby both proteolytic and nonproteolytic strains and therefore can berecovered in either the active or inactive form. However, even theproteolytic strains that produce, for example, the botulinum toxin typeB serotype only cleave a portion of the toxin produced. The exactproportion of nicked to unnicked molecules depends on the length ofincubation and the temperature of the culture. Therefore, a certainpercentage of any preparation of, for example, the botulinum toxin typeB toxin is likely to be inactive, possibly accounting for the knownsignificantly lower potency of botulinum toxin type B as compared tobotulinum toxin type A. The presence of inactive botulinum toxinmolecules in a clinical preparation will contribute to the overallprotein load of the preparation, which has been linked to increasedantigenicity, without contributing to its clinical efficacy.Additionally, it is known that botulinum toxin type B has, uponintramuscular injection, a shorter duration of activity and is also lesspotent than botulinum toxin type A at the same dose level.

High quality crystalline botulinum toxin type A can be produced from theHall A strain of Clostridium botulinum with characteristics of ≧3×10⁷U/mg, an A₂₆₀/A₂₇₈ of less than 0.60 and a distinct pattern of bandingon gel electrophoresis. The known Shantz process can be used to obtaincrystalline botulinum toxin type A, as set forth in Shantz, E. J., etal, Properties and use of Botulinum toxin and Other MicrobialNeurotoxins in Medicine, Microbiol Rev. 56; 80-99:1992. Generally, thebotulinum toxin type A complex can be isolated and purified from ananaerobic fermentation by cultivating Clostridium botulinum type A in asuitable medium. The known process can also be used, upon separation outof the non-toxin proteins, to obtain pure botulinum toxins, such as forexample: purified botulinum toxin type A with an approximately 150 kDmolecular weight with a specific potency of 1-2×10⁸ LD₅₀ U/mg orgreater; purified botulinum toxin type B with an approximately 156 kDmolecular weight with a specific potency of 1-2×10⁸ LD₅₀ U/mg orgreater, and; purified botulinum toxin type F with an approximately 155kD molecular weight with a specific potency of 1-2×10⁷ LD₅₀ U/mg orgreater.

Botulinum toxins and/or botulinum toxin complexes can be obtained fromList Biological Laboratories, Inc., Campbell, Calif.; the Centre forApplied Microbiology and Research, Porton Down, U.K.; Wako (Osaka,Japan), Metabiologics (Madison, Wis.) as well as from Sigma Chemicals ofSt Louis, Mo. Pure botulinum toxin can also be used to prepare apharmaceutical composition.

As with enzymes generally, the biological activities of the botulinumtoxins (which are intracellular peptidases) is dependant, at least inpart, upon their three dimensional conformation. Thus, botulinum toxintype A is detoxified by heat, various chemicals surface stretching andsurface drying. Additionally, it is known that dilution of the toxincomplex obtained by the known culturing, fermentation and purificationto the much, much lower toxin concentrations used for pharmaceuticalcomposition formulation results in rapid detoxification of the toxinunless a suitable stabilizing agent is present. Dilution of the toxinfrom milligram quantities to a solution containing nanograms permilliliter presents significant difficulties because of the rapid lossof specific toxicity upon such great dilution. Since the toxin may beused months or years after the toxin containing pharmaceuticalcomposition is formulated, the toxin can stabilized with a stabilizingagent such as albumin and gelatin.

A commercially available botulinum toxin containing pharmaceuticalcomposition is sold under the trademark BOTOX® (available from Allergan,Inc., of Irvine, Calif.). BOTOX® consists of a purified botulinum toxintype A complex, albumin and sodium chloride packaged in sterile,vacuum-dried form. The botulinum toxin type A is made from a culture ofthe Hall strain of Clostridium botulinum grown in a medium containingN—Z amine and yeast extract. The botulinum toxin type A complex ispurified from the culture solution by a series of acid precipitations toa crystalline complex consisting of the active high molecular weighttoxin protein and an associated hemagglutinin protein. The crystallinecomplex is re-dissolved in a solution containing saline and albumin andsterile filtered (0.2 microns) prior to vacuum-drying. The vacuum-driedproduct is stored in a freezer at or below −5° C. BOTOX® can bereconstituted with sterile, non-preserved saline prior to intramuscularinjection. Each vial of BOTOX® contains about 100 units (U) ofClostridium botulinum toxin type A purified neurotoxin complex, 0.5milligrams of human serum albumin and 0.9 milligrams of sodium chloridein a sterile, vacuum-dried form without a preservative.

To reconstitute vacuum-dried BOTOX®, sterile normal saline without apreservative; (0.9% Sodium Chloride Injection) is used by drawing up theproper amount of diluent in the appropriate size syringe. Since BOTOX®may be denatured by bubbling or similar violent agitation, the diluentis gently injected into the vial. For sterility reasons BOTOX® ispreferably administered within four hours after the vial is removed fromthe freezer and reconstituted. During these four hours, reconstitutedBOTOX® can be stored in a refrigerator at about 2° C. to about 8° C.Reconstituted, refrigerated BOTOX® has been reported to retain itspotency for at least about two weeks. Neurology, 48:249-53:1997.

It has been reported that botulinum toxin type A has been used inclinical settings as follows:

(1) about 75-125 units of BOTOX® per intramuscular injection (multiplemuscles) to treat cervical dystonia;

(2) 5-10 units of BOTOX® per intramuscular injection to treat glabellarlines (brow furrows) (5 units injected intramuscularly into the procerusmuscle and 10 units injected intramuscularly into each corrugatorsupercilii muscle);

(3) about 30-80 units of BOTOX® to treat constipation byintersphincteric injection of the puborectalis muscle;

(4) about 1-5 units per muscle of intramuscularly injected BOTOX® totreat blepharospasm by injecting the lateral pre-tarsal orbicularisoculi muscle of the upper lid and the lateral pre-tarsal orbicularisoculi of the lower lid.

(5) to treat strabismus, extraocular muscles have been injectedintramuscularly with between about 1-5 units of BOTOX®, the amountinjected varying based upon both the size of the muscle to be injectedand the extent of muscle paralysis desired (i.e. amount of dioptercorrection desired).(6) to treat upper limb spasticity following stroke by intramuscularinjections of BOTOX® into five different upper limb flexor muscles, asfollows:(a) flexor digitorum profundus: 7.5 U to 30 U(b) flexor digitorum sublimis: 7.5 U to 30 U(c) flexor carpi ulnaris: 10 U to 40 U(d) flexor carpi radialis: 15 U to 60 U(e) biceps brachii: 50 U to 200 U. Each of the five indicated muscleshas been injected at the same treatment session, so that the patientreceives from 90 U to 360 U of upper limb flexor muscle BOTOX® byintramuscular injection at each treatment session.(7) to treat migraine, pericranial injected (injected symmetrically intoglabellar, frontalis and temporalis muscles) injection of 25 U of BOTOX®has showed significant benefit as a prophylactic treatment of migrainecompared to vehicle as measured by decreased measures of migrainefrequency, maximal severity, associated vomiting and acute medicationuse over the three month period following the 25 U injection.

Additionally, intramuscular botulinum toxin has been used in thetreatment of tremor in patients with Parkinson's disease, although ithas been reported that results have not been impressive. Marjama-Jyons,J., et al., Tremor-Predominant Parkinson's Disease, Drugs & Aging 16(4);273-278:2000.

It is known that botulinum toxin type A can have an efficacy for up to12 months (European J. Neurology 6 (Supp 4): S111-S1150:1999), and insome circumstances for as long as 27 months, when used to treat glands,such as in the treatment of hyperhydrosis. See e.g. Bushara K.,Botulinum toxin and rhinorrhea, Otolaryngol Head Neck Surg 1996;114(3):507, and The Laryngoscope 109:1344-1346:1999. However, the usualduration of an intramuscular injection of Botox® is typically about 3 to4 months.

The success of botulinum toxin type A to treat a variety of clinicalconditions has led to interest in other botulinum toxin serotypes. Twocommercially available botulinum type A preparations for use in humansare BOTOX® available from Allergan, Inc., of Irvine, Calif., andDysport® available from Beaufour Ipsen, Porton Down, England. ABotulinum toxin type B preparation (MyoBloc®) is available from ElanPharmaceuticals of San Francisco, Calif.

In addition to having pharmacologic actions at the peripheral location,botulinum toxins may also have inhibitory effects in the central nervoussystem. Work by Weigand et al, Naunyn-Schmiedeberg's Arch. Pharmacol.1976; 292, 161-165, and Habermann, Naunyn-Schmiedeberg's Arch.Pharmacol. 1974; 281, 47-56 showed that botulinum toxin is able toascend to the spinal area by retrograde transport. As such, a botulinumtoxin injected at a peripheral location, for example intramuscularly,may be retrograde transported to the spinal cord.

U.S. Pat. No. 5,989,545 discloses that a modified clostridial neurotoxinor fragment thereof, preferably a botulinum toxin, chemically conjugatedor recombinantly fused to a particular targeting moiety can be used totreat pain by administration of the agent to the spinal cord.

It has been reported that use of a botulinum toxin to treat variousspasmodic muscle conditions can result in reduced depression andanxiety, as the muscle spasm is reduced. Murry T., et al., Spasmodicdysphonia; emotional status and botulinum toxin treatment, ArchOtolaryngol 1994 March; 120(3): 310-316; Jahanshahi M., et al.,Psychological functioning before and after treatment of torticollis withbotulinum toxin, J Neurol Neurosurg Psychiatry 1992; 55(3): 229-231.Additionally, German patent application DE 101 50 415 A1 discussesintramuscular injection of a botulinum toxin to treat depression andrelated affective disorders.

A botulinum toxin has also been proposed for or has been used to treatskin wounds (U.S. Pat. No. 6,447,787), various autonomic nervedysfunctions (U.S. Pat. No. 5,766,605), tension headache, (U.S. Pat. No.6,458,365), migraine headache pain (U.S. Pat. No. 5,714,468), sinusheadache (U.S. patent application Ser. No. 429,069), post-operative painand visceral pain (U.S. Pat. No. 6,464,986), neuralgia pain (U.S. patentapplication Ser. No. 630,587), hair growth and hair retention (U.S. Pat.No. 6,299,893), dental related ailments (U.S. provisional patentapplication Ser. No. 60/418,789), fibromyalgia (U.S. Pat. No.6,623,742), various skin disorders (U.S. patent application Ser. No.10/731,973), motion sickness (U.S. patent application Ser. No. 752,869),psoriasis and dermatitis (U.S. Pat. No. 5,670,484), injured muscles(U.S. Pat. No. 6,423,319) various cancers (U.S. Pat. No. 6,139,845),smooth muscle disorders (U.S. Pat. No. 5,437,291), down turned mouthcorners (U.S. Pat. No. 6,358,917), nerve entrapment syndromes (U.S.patent application 2003 0224019), various impulse disorders (U.S. patentapplication Ser. No. 423,380), acne (WO 03/011333) and neurogenicinflammation (U.S. Pat. No. 6,063,768). Controlled release toxinimplants are known (see e.g. U.S. Pat. Nos. 6,306,423 and 6,312,708) asis transdermal botulinum toxin administration (U.S. patent applicationSer. No. 10/194,805).

Botulinum toxin type A has been used to treat epilepsia partialiscontinua, a type of focal motor epilepsy. Bhattacharya K., et al., Noveluses of botulinum toxin type A: two case reports, Mov Disord 2000;15(Suppl 2):51-52.

It is known that a botulinum toxin can be used to: weaken the chewing orbiting muscle of the mouth so that self inflicted wounds and resultingulcers can heal (Payne M., et al, Botulinum toxin as a novel treatmentfor self mutilation in Lesch-Nyhan syndrome, Ann Neurol 2002 September;52(3 Supp 1):S157); permit healing of benign cystic lesions or tumors(Blugerman G., et al., Multiple eccrine hidrocystomas: A new therapeuticoption with botulinum toxin, Dermatol Surg 2003 May; 29(5):557-9); treatanal fissure (Jost W., Ten years' experience with botulinum toxin inanal fissure, Int J Colorectal Dis 2002 September; 17(5):298-302, and;treat certain types of atopic dermatitis (Heckmann M., et al., Botulinumtoxin type A injection in the treatment of lichen simplex: An open pilotstudy, J Am Acad Dermatol 2002 April; 46(4):617-9).

Additionally, a botulinum toxin may have an effect to reduce inducedinflammatory pain in a rat formalin model. Aoki K., et al, Mechanisms ofthe antinociceptive effect of subcutaneous Botox: Inhibition ofperipheral and central nociceptive processing, Cephalalgia 2003September; 23(7):649. Furthermore, it has been reported that botulinumtoxin nerve blockage can cause a reduction of epidermal thickness. Li Y,et al., Sensory and motor denervation influences epidermal thickness inrat foot glabrous skin, Exp Neurol 1997; 147:452-462 (see page 459).Finally, it is known to administer a botulinum toxin to the foot totreat excessive foot sweating (Katsambas A., et al., Cutaneous diseasesof the foot: Unapproved treatments, Clin Dermatol 2002November-December; 20(6):689-699; Sevim, S., et al., Botulinum toxin-Atherapy for palmar and plantar hyperhidrosis, Acta Neurol Belg 2002December; 102(4):167-70), spastic toes (Suputtitada, A., Local botulinumtoxin type A injections in the treatment of spastic toes, Am J Phys MedRehabil 2002 October; 81(10):770-5), idiopathic toe walking (Tacks, L.,et al., Idiopathic toe walking: Treatment with botulinum toxin Ainjection, Dev Med Child Neurol 2002; 44(Suppl 91):6), and foot dystonia(Rogers J., et al., Injections of botulinum toxin A in foot dystonia,Neurology 1993 April; 43(4 Suppl 2)).

Tetanus toxin, as wells as derivatives (i.e. with a non-native targetingmoiety), fragments, hybrids and chimeras thereof can also havetherapeutic utility. The tetanus toxin bears many similarities to thebotulinum toxins. Thus, both the tetanus toxin and the botulinum toxinsare polypeptides made by closely related species of Clostridium(Clostridium tetani and Clostridium botulinum, respectively).

Additionally, both the tetanus toxin and the botulinum toxins aredichain proteins composed of a light chain (molecular weight about 50kD) covalently bound by a single disulfide bond to a heavy chain(molecular weight about 100 kD). Hence, the molecular weight of tetanustoxin and of each of the seven botulinum toxins (non-complexed) is about150 kD. Furthermore, for both the tetanus toxin and the botulinumtoxins, the light chain bears the domain which exhibits intracellularbiological (protease) activity, while the heavy chain comprises thereceptor binding (immunogenic) and cell membrane translocationaldomains.

Further, both the tetanus toxin and the botulinum toxins exhibit a high,specific affinity for ganglioside receptors on the surface ofpresynaptic cholinergic neurons. Receptor mediated endocytosis oftetanus toxin by peripheral cholinergic neurons results in retrogradeaxonal transport, blocking of the release of inhibitoryneurotransmitters from central synapses and a spastic paralysis.Contrarily, receptor mediated endocytosis of botulinum toxin byperipheral cholinergic neurons results in little if any retrogradetransport, inhibition of acetylcholine exocytosis from the intoxicatedperipheral motor neurons and a flaccid paralysis.

Finally, the tetanus toxin and the botulinum toxins resemble each otherin both biosynthesis and molecular architecture. Thus, there is anoverall 34% identity between the protein sequences of tetanus toxin andbotulinum toxin type A, and a sequence identity as high as 62% for somefunctional domains. Binz T. et al., The Complete Sequence of BotulinumNeurotoxin Type A and Comparison with Other Clostridial Neurotoxins, JBiological Chemistry 265(16); 9153-9158:1990.

Acetylcholine

Typically only a single type of small molecule neurotransmitter isreleased by each type of neuron in the mammalian nervous system,although there is evidence which suggests that several neuromodulatorscan be released by the same neuron. The neurotransmitter acetylcholineis secreted by neurons in many areas of the brain, but specifically bythe large pyramidal cells of the motor cortex, by several differentneurons in the basal ganglia, by the motor neurons that innervate theskeletal muscles, by the preganglionic neurons of the autonomic nervoussystem (both sympathetic and parasympathetic), by the bag 1 fibers ofthe muscle spindle fiber, by the postganglionic neurons of theparasympathetic nervous system, and by some of the postganglionicneurons of the sympathetic nervous system. Essentially, only thepostganglionic sympathetic nerve fibers to the sweat glands, thepiloerector muscles and a few blood vessels are cholinergic as most ofthe postganglionic neurons of the sympathetic nervous system secret theneurotransmitter norepinephrine. In most instances acetylcholine has anexcitatory effect. However, acetylcholine is known to have inhibitoryeffects at some of the peripheral parasympathetic nerve endings, such asinhibition of heart rate by the vagal nerve.

The efferent signals of the autonomic nervous system are transmitted tothe body through either the sympathetic nervous system or theparasympathetic nervous system. The preganglionic neurons of thesympathetic nervous system extend from preganglionic sympathetic neuroncell bodies located in the intermediolateral horn of the spinal cord.The preganglionic sympathetic nerve fibers, extending from the cellbody, synapse with postganglionic neurons located in either aparavertebral sympathetic ganglion or in a prevertebral ganglion. Since,the preganglionic neurons of both the sympathetic and parasympatheticnervous system are cholinergic, application of acetylcholine to theganglia will excite both sympathetic and parasympathetic postganglionicneurons.

Acetylcholine activates two types of receptors, muscarinic and nicotinicreceptors. The muscarinic receptors are found in all effector cellsstimulated by the postganglionic, neurons of the parasympathetic nervoussystem as well as in those stimulated by the postganglionic cholinergicneurons of the sympathetic nervous system. The nicotinic receptors arefound in the adrenal medulla, as well as within the autonomic ganglia,that is on the cell surface of the postganglionic neuron at the synapsebetween the preganglionic and postganglionic neurons of both thesympathetic and parasympathetic systems. Nicotinic receptors are alsofound in many nonautonomic nerve endings, for example in the membranesof skeletal muscle fibers at the neuromuscular junction.

Acetylcholine is released from cholinergic neurons when small, clear,intracellular vesicles fuse with the presynaptic neuronal cell membrane.A wide variety of non-neuronal secretory cells, such as, adrenal medulla(as well as the PC12 cell line) and pancreatic islet cells releasecatecholamines and parathyroid hormone, respectively, from largedense-core vesicles. The PC12 cell line is a clone of ratpheochromocytoma cells extensively used as a tissue culture model forstudies of sympathoadrenal development. Botulinum toxin inhibits therelease of both types of compounds from both types of cells in vitro,permeabilized (as by electroporation) or by direct injection of thetoxin into the denervated cell. Botulinum toxin is also known to blockrelease of the neurotransmitter glutamate from cortical synaptosomescell cultures.

A neuromuscular junction is formed in skeletal muscle by the proximityof axons to muscle cells. A signal transmitted through the nervoussystem results in an action potential at the terminal axon, withactivation of ion channels and resulting release of the neurotransmitteracetylcholine from intraneuronal synaptic vesicles, for example at themotor endplate of the neuromuscular junction. The acetylcholine crossesthe extracellular space to bind with acetylcholine receptor proteins onthe surface of the muscle end plate. Once sufficient binding hasoccurred, an action potential of the muscle cell causes specificmembrane ion channel changes, resulting in muscle cell contraction. Theacetylcholine is then released from the muscle cells and metabolized bycholinesterases in the extracellular space. The metabolites are recycledback into the terminal axon for reprocessing into further acetylcholine.

What is needed therefore is an effective method for preventing headachesand for treating medication overuse disorders. What is also needed is amethod for increasing the effectiveness of a triptan to treat aheadache, as such a method could permit lower dosages of a triptan to beused.

SUMMARY

The present invention meets this need and provides methods foreffectively preventing headaches, treating pain and for treatingmedication overuse disorders (MOD), by local administration of aClostridial toxin. Our invention also provides a method for increasingthe effectiveness of a triptan to treat a headache.

A method according to our invention can be carried out by administrationof a Clostridial toxin to a patient with a MOD. The Clostridial toxinused is preferably a botulinum toxin (as either a complex or as a pure[i.e. about 150 kDa molecule], such as a botulinum toxin A, B, C, D, E,F or G. Administration of the Clostridial toxin can be by a transdermalroute (i.e. by application of a Clostridial toxin in a cream, patch orlotion vehicle), subdermal route (i.e. subcutaneous or intramuscular),or intradermal route of administration.

A hypothesized physiological reason for the efficacy of our invention,as explained in greater detail below, is to reduce, inhibit or eliminatesensory input (afferent) from the periphery into the central nervoussystem (including to the brain) which is perceived by the patient aspain and/or which engenders development of a medication overusedisorder. Such pain sensory input can be attenuated or eliminated bytargeting subdermal sensory neurons with a low dose of a Clostridialtoxin.

The dose of a Clostridial toxin used according to the present inventionis less than the amount of Clostridial toxin (such as a botulinum toxin)that would be used to paralyze a muscle, since an intent of a methodaccording to the present invention is not to paralyze a muscle but toreduce a pain sensory output from sensory neurons located in or on amuscle, or in or under the skin.

The following definitions apply herein:

“About” means approximately or nearly and in the context of a numericalvalue or range set forth herein means±10% of the numerical value orrange recited or claimed.

“Alleviating” means a reduction in the occurrence of a pain, of aheadache or of a symptom of a MOD. Thus, alleviating includes somereduction, significant reduction, near total reduction, and totalreduction.

An alleviating effect may not appear clinically for between 1 to 7 daysafter administration of a Clostridial toxin to a patient.

“Botulinum toxin” means a botulinum neurotoxin as either pure toxin orcomplex, and excludes botulinum toxins which are not neurotoxins such asthe cytotoxic botulinum toxins C₂ and C₃.

“Local administration” means administration (i.e. by a subcutaneous,intramuscular, subdermal or transdermal route) of a pharmaceutical agentto or to the vicinity of a muscle or of a subdermal location or in thehead of a patient by a non-systemic route. Thus, local administrationexcludes systemic (i.e. to the blood circulation system) routes ofadministration, such as intravenous or oral administration. Peripheraladministration means administration to the periphery (i.e. to a locationon or within a limb, trunk or head of a patient) as opposed to avisceral or gut (i.e. to the viscera) administration.

“Treating” means to alleviate (or to eliminate) at least one symptom ofpain (such as a headache pain) or of a MOD, either temporarily orpermanently.

The Clostridial neurotoxin is administered in a therapeuticallyeffective amount to alleviate pain, to prevent a headache or to treat asymptom of a MOD. A suitable Clostridial neurotoxin may be a neurotoxinmade by a bacterium, for example, the neurotoxin may be made from aClostridium botulinum, Clostridium butyricum, or Clostridium baratii. Incertain embodiments of the invention, the disorder can be treated byintramuscular (facial) administration a botulinum toxin to the patient.The botulinum toxin may be a botulinum toxin type A, type B, type C₁,type D, type E, type F, or type G. The pain and/or MOD alleviatingeffects of the botulinum toxin may persist for between about 1 month and5 years. The botulinum neurotoxin can be a recombinantly made botulinumneurotoxins, such as botulinum toxins produced by E. coli. In additionor alternatively, the botulinum neurotoxin can be a modified neurotoxin,that is a botulinum neurotoxin which has at least one of its amino acidsdeleted, modified or replaced, as compared to a native or the modifiedbotulinum neurotoxin can be a recombinant produced botulinum neurotoxinor a derivative or fragment thereof.

A method for treating a MOD according to the present invention cancomprise the step of local administration of a botulinum toxin to apatient with a MOD to thereby alleviate the MOD. The botulinum toxin canbe selected from the group consisting of botulinum toxin types A, B, C,D, E, F and G. Botulinum toxin type A is a preferred botulinum toxin.The botulinum toxin can be administered in an amount of between about 1unit and about 3,000 units and the alleviation of the MOD can persistfor between about 1 month and about 5 years. The local administration ofthe botulinum toxin can be to or to a vicinity of where the patientexperiences or is predisposed to experience pain. Alternately, the localadministration can be by intramuscular injection or to a subdermallocation from which the patient perceives the existence of a pain toarise, typically at the forehead.

Another embodiment of our invention is a method for treating a headachein a triptan medication overuse patient. The method can comprise thestep of local administration of a botulinum toxin to a patient who is atriptan medication overuse patient, thereby both countering a headacheexacerbation caused by triptan medication overuse and reducing the useof triptan medication by the patient to treat a headache.

A further embodiment of our invention is a method for increasing theeffectiveness of a triptan medication to treat a headache. The methodcan comprise the step of administering a triptan to treat a headache andlocal administration of a botulinum toxin.

DRAWINGS

The following drawings are presented to assist understanding of aspectsand features of the present invention.

FIG. 1 is a graph which shows results (mean change in the number ofheadaches per thirty day period) of a clinical study carried out for useof BOTOX to inter alia treat migraine headache, showing that thepatients had fewer headaches after administration of BOTOX. In all thedata shown in all the Figures the patients had been administered BOTOXat days 0, 90 and 180.

FIG. 2 is a graph which shows results (mean change in the number of dayswhen the patients were concurrently taking acute headache painalleviation medication per thirty day period) of a clinical studycarried out for use of BOTOX to inter alia treat migraine headache,showing that the patients had fewer days when they were taking acuteheadache pain alleviation medication after administration of BOTOX.

FIG. 3 is a graph which shows a comparison of the percent of patients(some who had been administered BOTOX and some who had been administereda placebo) who were over a thirty day period using narcotics medicationto control acute headache pain. FIG. 3 shows a decrease in narcotics usein the BOTOX treated patients.

FIG. 4 is a graph which shows results that there was a decrease in thepercent of patients who had acute headache medication overuse in athirty day period after administration of BOTOX.

FIG. 5 is a graph which shows that there was a decrease in the percentof patients who had triptans acute headache medication overuse in athirty day period after administration of BOTOX.

FIG. 6 comprises two graphs which shows the mean change in the number ofheadaches experienced by patients over a thirty day period afteradministration of BOTOX, where the patients either did not have amedication overuse disorder (“without MOU”) (left hand side graph) orthe patients did have a medication overuse disorder (right hand sidegraph). “≧15 days and ≧2 days/week” are criteria used to determine thata patient had a medication overuse (“MOU”) disorder. MOU and MOD aresynonymous terms. By definition a patient has a MOU disorder if he orshe takes an acute medication 15 or more days per month and at leasttwice a week in the week that they are experiencing the acute pain.

FIG. 7 comprises two graphs which show the mean change from baseline inthe frequency of headaches per 30-day period in patients using (graph A)and not using (graph B) prophylactic headache medications at baseline,for a pooled population of patients. The Y-axis represents the meanchange in the number of headaches per thirty day period. “n” means thenumber of patients in the sample of patients evaluated.

FIG. 8 comprises two graphs which shows the mean change in the number ofheadaches experienced by patients over a thirty day period afteradministration of BOTOX, where the patients either were not concurrentlyusing another headache prophylaxis treatment (left hand side graph) orthe patients were not concurrently using another headache prophylaxistreatment and did have a medication overuse disorder (right hand sidegraph). The prophylaxis is used by the patient to prevent the headacheand is taken daily by the patient whether or not the patient has aheadache. Acute medications are used only as needed to treat a headache.MOU relates only to how frequently the patient uses acute medications.

FIG. 9 comprises two graphs which shows the mean change in the number ofheadaches experienced by patients over a thirty day period afteradministration of BOTOX, where the patients either were not concurrentlyusing another headache prophylaxis treatment and did not have amedication overuse disorder (left hand side graph) or the patients werenot concurrently using another headache prophylaxis treatment and didhave a medication overuse disorder (right hand side graph).

FIG. 10 is a bar chart showing the percentage of patients over a thirtyday period after administration of BOTOX who were also using an opioidacute headache medication to control their headaches.

FIG. 11 comprises two graphs which shows the mean change in the numberof headaches experienced by patients over a thirty day period afteradministration of BOTOX, where the patients either were triptanmedication overuse patients (left hand side graph) or the patients werenot triptan medication overuse patients (right hand side graph).

FIG. 12 comprises two graphs which shows the mean change from baseline(after administration of BOTOX) in number of days with acute headache(analgesic) medication use by the patients, where the patients wereeither triptan medication overuse patients (left hand side graph) or thepatients were not triptan medication overuse patients (right hand sidegraph).

FIG. 13 comprises on the left side, a left side diagrammatic view ofhuman muscle anatomy from the shoulders up, and on the right side ofFIG. 13 a diagrammatic view of the back or trunk (including the neck),both views in FIG. 13 showing the anatomy and placement of the muscleswith the overlying skin removed.

FIG. 14 comprises two graphs which show the mean change from baseline inthe frequency of headaches per 30-day period for placebo non-responders(graph A) and placebo responders (graph B).

FIG. 15 is a graph which shows the mean change from baseline in thefrequency of headaches per 30-day period, for a pooled population ofpatients.

FIG. 16 comprises two graphs which show mean change from baseline in thenumber of days of use of acute analgesic headache medications per 30-dayperiod for patients using (graph A) and not using (graph B) prophylacticheadache medications at baseline, for a pooled population of patients.

DESCRIPTION

The present invention is based on the discovery that a botulinum toxincan be used to treat a patient who is overusing a pain alleviationmedication to treat his or her pain (such as a headache pain), to reduceboth (a) the number of headaches experienced by the patient (see FIG. 1)and (b) the daily use of acute headache pain medication by the patient(FIG. 2). In particular we have found (see FIG. 3) that a botulinumtoxin can be used to reduce use by patients of narcotic pain medication.Medication overuse to treat headache pain (“MOH”) is a recognizeddisorder.

Additionally, we found that use of a botulinum toxin in patients whowere overusing pain alleviation medication experienced a significantreduction in their use of such medications after treatment with abotulinum toxin (see FIG. 4). We also found that there was a significantreduction in the intake of triptan medications in triptan medicationoveruse patients (see FIG. 5).

Our invention can also be used as part of a detoxification protocolwhereby a patient who is being weaned off acute pain medications isfacilitated in this goal by concurrent administration of a botulinumtoxin. Our invention can also be used to treat other chronic painconditions (e.g. back pain, neuropathic pain, allodynia, fibromyalgia,etc.) which can include patients that overuse acute medications,specifically narcotics and triptans.

According to our invention, a medication overuse disorder can be treatedby local administration of a therapeutically effective amount of abotulinum toxin. Thus, a botulinum toxin (such as a botulinum toxinserotype A, B, C₁, D, E, F or G) can be injected (i.e. intramuscularinjection) into or in the vicinity where a patient is experiencing thepain to thereby suppress the pain or prevent its occurrence.Alternately, the botulinum toxin can be administered to an intradermalor subdermal pain sensory neuron thereby suppressing and treating such amedication overuse disorder.

Our invention is preferably practised by administering a botulinum toxindirectly to a location where a patient is or is predisposed toexperience pain. Without wishing to be bound by theory a physiologicalmechanism can be proposed for the efficacy of the present invention. Itis known that muscles have a complex system of innervation and sensoryoutput. Thus, anterior motor neurons located in each segment of theanterior horns of the spinal cord gray matter give rise to efferentalpha motor neurons and efferent gamma motor neurons that leave thespinal cord by way of the anterior roots to innervate skeletal(extrafusal) muscle fibers. The alpha motor neurons cause contraction ofextrafusal skeletal muscle fibers while the gamma motor neuronsinnervate the intrafusal fibers of skeletal muscle. As well asexcitation by these two type of efferent anterior motor neuronprojections, there are additional, afferent sensory neurons whichproject from muscle spindle and golgi tendon organs and act to transmitinformation regarding various muscle parameter status to the spinalcord, cerebellum and cerebral cortex. These afferent motor neurons whichrelay sensory information from the muscle spindle include type Ia andtype II sensory afferent neurons. See e.g. pages 686-688 of Guyton A. C.et al., Textbook of Medical Physiology, W.B. Saunders Company 1996,ninth edition.

Significantly, it has been determined that a botulinum toxin can act toreduce transmission of sensory information from muscle type Ia afferentneurons. Aoki, K., Physiology and pharmacology of therapeutic botulinumneurotoxins, in Kreyden, O., editor, Hyperhydrosis and botulinum toxinin dermatology, Basel, Karger; 2002; 30: pages 107-116, at 109-110. Andit has been hypothesized that botulinum toxin can have a direct effectupon muscle cell sensory afferents and modify signals from theseafferents to the central nervous system. See e.g. Brin, M., et al.,Botulinum toxin type A: pharmacology, in Mayer N., editor, Spasticity:etiology, evaluation, management and the role of botulinum toxin, 2002;pages 110-124, at 112-113; Cui, M., et al., Mechanisms of theantinociceptive effect of subcutaneous BOTOX®: inhibition of peripheraland central nociceptive processing, Naunyn Schmiedebergs Arch Pharmacol2002; 365 (supp 2): R17; Aoki, K., et al., Botulinum toxin type A andother botulinum toxin serotypes: a comparative review of biochemical andpharmacological actions, Eur J. Neurol 2001: (suppl 5); 21-29. Thus, ithas been demonstrated that botulinum toxin can cause an altered sensoryoutput from muscle to CNS and brain.

Importantly, the sensory neurons from which afferent output is to beinhibited by a method according to the present invention need not belocated on or within a muscle, but can be in an intradermal or subdermallocation.

Thus, pain can be due to sensory input from afferent facial areaneurons. Administration of a botulinum toxin to a facial muscles or skinto reduce sensory output from the muscle can result in alleviation ofand prevention of pain.

It is our hypothesis, as may be the case in the treatment of a migraineheadache with a botulinum toxin, that signals transmitted by afferentpain nerves in or on muscle tissue (i.e. muscle spindle fibers andmuscle pain fibers) or as a part of sensory structures in the skin orsubdermally induce the pain sensation. That is, afferent signal frommuscles or skin structures provide sensory information to the brainwhich then leads to the generation of pain. Thus, a local administrationof a botulinum toxin to muscle spindle fibers, pain fibers or othersensors in or in the vicinity of a muscle can act to alter the neuralsignal afferent output from these muscles to the brain and therebydecrease the sensation of pain.

Important elements of our invention are firstly that is practiced by useof a local administration of low dose of a botulinum toxin. The selectedlow dose may not cause a muscle paralysis. Secondly, the invention canbe practiced by local administration of the low dose of the botulinumtoxin to the muscle or to the muscle group which initiates the painsensation.

The amount of the Clostridial toxin administered according to a methodwithin the scope of the disclosed invention can vary according to theparticular characteristics of the pain being treated, including itsseverity and other various patient variables including size, weight,age, and responsiveness to therapy. To guide the practitioner,typically, no less than about 1 unit and no more than about 25 units ofa botulinum toxin type A (such as BOTOX®) is administered per injectionsite (i.e. to each muscle portion injected), per patient treatmentsession. For a botulinum toxin type A such as DYSPORT®, no less thanabout 2 units and no more about 125 units of the botulinum toxin type Aare administered per injection site, per patient treatment session. Fora botulinum toxin type B such as MYOBLOC®, no less than about 40 unitsand no more about 1500 units of the botulinum toxin type B areadministered per injection site, per patient treatment session. Lessthan about 1, 2 or 40 units (of BOTOX®, DYSPORT® and MYOBLOC®respectively) can fail to achieve a desired therapeutic effect, whilemore than about 25, 125 or 1500 units (of BOTOX®, DYSPORT® and MYOBLOC®respectively) can result in significant muscle hypotonicity, weaknessand/or paralysis.

More preferably: for BOTOX® no less than about 2 units and no more about20 units of a botulinum toxin type A; for DYSPORT® no less than about 4units and no more than about 100 units, and; for MYOBLOC®, no less thanabout 80 units and no more than about 1000 units are, respectively,administered per injection site, per patient treatment session.

Most preferably: for BOTOX® no less than about 5 units and no more about15 units of a botulinum toxin type A; for DYSPORT® no less than about 20units and no more than about 75 units, and; for MYOBLOC®, no less thanabout 200 units and no more than about 750 units are, respectively,administered per injection site, per patient treatment session. It isimportant to note that there can be multiple injection sites (i.e. apattern of injections) for each patient treatment session.

Generally, the total amount of BOTOX®, DYSPORT® or MYOBLOC®, suitablefor administration to a patient according to the methods of theinvention disclosed herein should not exceed about 300 units, about1,500 units or about 15,000 units respectively, per treatment session.

Although examples of routes of administration and dosages are provided,the appropriate route of administration and dosage are generallydetermined on a case by case basis by the attending physician. Suchdeterminations are routine to one of ordinary skill in the art (see forexample, Harrison's Principles of Internal Medicine (1998), edited byAnthony Fauci et al., 14^(th) edition, published by McGraw Hill). Forexample, the route and dosage for administration of a neurotoxinaccording to the present disclosed invention can be selected based uponcriteria such as the solubility characteristics of the neurotoxin chosenas well as the intensity of pain perceived.

The present invention is based on the discovery that localadministration of a Clostridial toxin can provide significant and longlasting relief and prevention of pain and treatment of a medicationoveruse disorder. The Clostridial toxins used in accordance with theinvention disclosed herein can inhibit transmission of chemical orelectrical signals between select neuronal groups that are involved ingeneration of pain. The Clostridial toxins preferably are not cytotoxicto the cells that are exposed to the Clostridial toxin. The Clostridialtoxin can inhibit neurotransmission by reducing or preventing exocytosisof neurotransmitter from the neurons exposed to the Clostridial toxin.Or the applied Clostridial toxin can reduce neurotransmission byinhibiting the generation of action potentials of the neurons exposed tothe toxin. The headache and headache pain prevention and alleviationeffects provided by the Clostridial toxin can persist for a relativelylong period of time, for example, for more than two months, andpotentially for several years.

Examples of Clostridial toxins within the scope of the present inventioninclude neurotoxins made by Clostridium botulinum, Clostridium butyricumand Clostridium baratii species. In addition, the botulinum toxins usedin the methods of the invention may be a botulinum toxin selected from agroup of botulinum toxin types A, B, C, D, E, F, and G. In oneembodiment of the invention, the botulinum neurotoxin administered tothe patient is botulinum toxin type A. Botulinum toxin type A isdesirable due to its high potency in humans, ready availability, andknown use for the treatment of skeletal and smooth muscle disorders whenlocally administered by intramuscular injection. The present inventionalso includes the use of (a) Clostridial neurotoxins obtained orprocessed by bacterial culturing, toxin extraction, concentration,preservation, freeze drying, and/or reconstitution; and/or (b) modifiedor recombinant neurotoxins, that is neurotoxins that have had one ormore amino acids or amino acid sequences deliberately deleted, modifiedor replaced by known chemical/biochemical amino acid modificationprocedures or by use of known host cell/recombinant vector recombinanttechnologies, as well as derivatives or fragments of neurotoxins somade. These neurotoxin variants retain the ability to inhibitneurotransmission between or among neurons, and some of these variantsmay provide increased durations of inhibitory effects as compared tonative neurotoxins, or may provide enhanced binding specificity to theneurons exposed to the neurotoxins. These neurotoxin variants may beselected by screening the variants using conventional assays to identifyneurotoxins that have the desired physiological effects of inhibitingneurotransmission.

Botulinum toxins for use according to the present invention can bestored in lyophilized, vacuum dried form in containers under vacuumpressure or as stable liquids. Prior to lyophilization the botulinumtoxin can be combined with pharmaceutically acceptable excipients,stabilizers and/or carriers, such as albumin. The lyophilized materialcan be reconstituted with saline or water to create a solution orcomposition containing the botulinum toxin to be administered to thepatient.

Although the composition may only contain a single type of neurotoxin,such as botulinum toxin type A, as the active ingredient to suppressneurotransmission, other therapeutic compositions may include two ormore types of neurotoxins, which may provide enhanced therapeutictreatment of a headache. For example, a composition administered to apatient may include botulinum toxin type A and botulinum toxin type B.Administering a single composition containing two different neurotoxinsmay permit the effective concentration of each of the neurotoxins to belower than if a single neurotoxin is administered to the patient whilestill achieving the desired therapeutic effects. The compositionadministered to the patient may also contain other pharmaceuticallyactive ingredients, such as, protein receptor or ion channel modulators,in combination with the neurotoxin or neurotoxins. These modulators maycontribute to the reduction in neurotransmission between the variousneurons. For example, a composition may contain gamma aminobutyric acid(GABA) type A receptor modulators that enhance the inhibitory effectsmediated by the GABA_(A) receptor. The GABA_(A) receptor inhibitsneuronal activity by effectively shunting current flow across the cellmembrane. GABA_(A) receptor modulators may enhance the inhibitoryeffects of the GABA_(A) receptor and reduce electrical or chemicalsignal transmission from the neurons. Examples of GABA_(A) receptormodulators include benzodiazepines, such as diazepam, oxazepam,lorazepam, prazepam, alprazolam, halazepam, chlordiazepoxide, andclorazepate. Compositions may also contain glutamate receptor modulatorsthat decrease the excitatory effects mediated by glutamate receptors.Examples of glutamate receptor modulators include agents that inhibitcurrent flux through AMPA, NMDA, and/or kainate types of glutamatereceptors. The compositions may also include agents that modulatedopamine receptors, such as antipsychotics, norepinephrine receptors,and/or serotonin receptors. The compositions may also include agentsthat affect ion flux through voltage gated calcium channels, potassiumchannels, and/or sodium channels. Thus, the compositions used to treatpain can include one or more neurotoxins, such as botulinum toxins, inaddition to ion channel receptor modulators that may reduceneurotransmission.

The neurotoxin may be administered by any suitable method as determinedby the attending physician. The methods of administration permit theneurotoxin to be administered locally to a selected target tissue.Methods of administration include injection of a solution or compositioncontaining the neurotoxin, as described above, and include implantationof a controlled release system that controllably releases the neurotoxinto the target tissue. Such controlled release systems reduce the needfor repeat injections. Diffusion of biological activity of a botulinumtoxin within a tissue appears to be a function of dose and can begraduated. Jankovic J., et al Therapy With Botulinum Toxin, MarcelDekker, Inc., (1994), page 150. Thus, diffusion of botulinum toxin canbe controlled to reduce potentially undesirable side effects that mayaffect the patient's cognitive abilities. For example, the neurotoxincan be administered so that the neurotoxin primarily effects neuralsystems believed to be involved in the generation of pain and/orinflammation, and does not have negatively adverse effects on otherneural systems.

A polyanhydride polymer, Gliadel® (Stolle R & D, Inc., Cincinnati, Ohio)a copolymer of poly-carboxyphenoxypropane and sebacic acid in a ratio of20:80 has been used to make implants, and has been intracraniallyimplanted to treat malignant gliomas. Polymer and BCNU can beco-dissolved in methylene chloride and spray-dried into microspheres.The microspheres can then be pressed into discs 1.4 cm in diameter and1.0 mm thick by compression molding, packaged in aluminum foil pouchesunder nitrogen atmosphere and sterilized by 2.2 megaRads of gammairradiation. The polymer permits release of carmustine over a 2-3 weekperiod, although it can take more than a year for the polymer to belargely degraded. Brem, H., et al, Placebo-Controlled Trial of Safetyand Efficacy of Intraoperative Controlled Delivery by BiodegradablePolymers of Chemotherapy for Recurrent Gliomas, Lancet 345;1008-1012:1995.

Implants useful in practicing the methods disclosed herein may beprepared by mixing a desired amount of a stabilized neurotoxin (such asnon-reconstituted BOTOX®) into a solution of a suitable polymerdissolved in methylene chloride. The solution may be prepared at roomtemperature. The solution can then be transferred to a Petri dish andthe methylene chloride evaporated in a vacuum desiccator. Depending uponthe implant size desired and hence the amount of incorporatedneurotoxin, a suitable amount of the dried neurotoxin incorporatingimplant is compressed at about 8000 p.s.i. for 5 seconds or at 3000p.s.i. for 17 seconds in a mold to form implant discs encapsulating theneurotoxin. See e.g. Fung L. K. et al., Pharmacokinetics of InterstitialDelivery of Carmustine 4-Hydroperoxycyclophosphamide and Paclitaxel Froma Biodegradable Polymer Implant in the Monkey Brain, Cancer Research 58;672-684:1998.

Local administration of a Clostridial toxin, such as a botulinum toxin,can provide a high, local therapeutic level of the toxin. A controlledrelease polymer capable of long term, local delivery of a Clostridialtoxin to a target muscle permits effective dosing of a target tissue. Asuitable implant, as set forth in U.S. Pat. No. 6,306,423 entitled“Neurotoxin Implant”, allows the direct introduction of achemotherapeutic agent to a target tissue via a controlled releasepolymer. The implant polymers used are preferably hydrophobic so as toprotect the polymer incorporated neurotoxin from water induceddecomposition until the toxin is released into the target tissueenvironment.

Local administration of a botulinum toxin, according to the presentinvention, by injection or implant to a target tissue provides asuperior alternative to systemic administration of pharmaceuticals topatients to alleviate pain and to treat a MOD such as MOH.

The amount of a Clostridial toxin selected for local administration to atarget tissue according to the present disclosed invention can be variedbased upon criteria such as the severity of the pain or type of headacheor MOD being treated, the extent of muscle tissue to be treated,solubility characteristics of the neurotoxin toxin chosen as well as theage, sex, weight and health of the patient. For example, the extent ofthe area of muscle tissue influenced is believed to be proportional tothe volume of neurotoxin injected, while the quantity of the suppressanteffect is, for most dose ranges, believed to be proportional to theconcentration of a Clostridial toxin administered. Methods fordetermining the appropriate route of administration and dosage aregenerally determined on a case by case basis by the attending physician.Such determinations are routine to one of ordinary skill in the art (seefor example, Harrison's Principles of Internal Medicine (1998), editedby Anthony Fauci et al., 14^(th) edition, published by McGraw Hill).

Significantly, a method within the scope of the present invention canprovide improved patient function. “Improved patient function” can bedefined as an improvement measured by factors such as a reduced pain,reduced time spent in bed, increased ambulation, healthier attitude,more varied lifestyle and/or healing permitted by normal muscle tone.Improved patient function is synonymous with an improved quality of life(QOL). QOL can be assessed using, for example, the known SF-12 or SF-36health survey scoring procedures. SF-36 assesses a patient's physicaland mental health in the eight domains of physical functioning, rolelimitations due to physical problems, social functioning, bodily pain,general mental health, role limitations due to emotional problems,vitality and general health perceptions. Scores obtained can be comparedto published values available for various general and patientpopulations.

EXAMPLE

The following non-limiting example provides those of ordinary skill inthe art with specific preferred methods to treat conditions within thescope of the present invention and are not intended to limit the scopeof the invention. In the following examples various modes ofnon-systemic administration of a Clostridial neurotoxin can be carriedout. For example, by intramuscular injection, subcutaneous injection orby implantation of a controlled release implant.

Example 1 Botulinum Toxin Type A Therapy for Headache Pain and for aMedication Overuse Headache Disorder Summary of the Study

A clinical study was carried out which included patients who complainedof headache pain and who took frequent acute pain medications, such asnarcotics and triptans to control the pain. Some of these patients werediagnosed with medication overuse headache (MOH) disorder. A botulinumtoxin (BOTOX) was administered to the patients in the study at threetimes during the clinical study: at day 0, at day 90 and at day 180. TheBOTOX injections were administered intramuscularly in an average of 20separate injections to each patient at each of the three injectionsessions. The BOTOX was administered to up to seven different muscles(i.e. 20 total injections into 7 muscles).

From 105 to 260 units of the BOTOX was administered to each patient ateach of the three treatment sessions. It was found that the patientsexperienced a reduction in both (a) the number of headaches experiencedby such patients (FIG. 1), and; (b) the daily use of acute headache painmedication by these patients (FIG. 2). In particular it was found (FIG.3) that a botulinum toxin can be used to reduce use by these patients ofnarcotic pain medication.

Additionally, it was found that use of a botulinum toxin in patients whowere overusing pain alleviation medication resulted in a significantreduction in their use of such medications after treatment with abotulinum toxin (see FIG. 4). It was also found that there was asignificant reduction in the intake of triptan medications in overusepatients (FIG. 5). Thus, this clinical study surprisingly showed that abotulinum toxin can be used to treat a medication overuse headachedisorder (MOH).

As set forth above, the study carried out showed that a botulinum toxinwas effective to treat headache in a patients overusing medications(referred to below as “MOU”, meaning medication overuse patients). Toreiterate, and as shown in FIG. 6, use of a botulinum toxin permitted asignificant reduction in number of headaches in the population that wasoverusing medication at baseline (i.e. at initiation of the study).

The study also demonstrated (see FIG. 7) that a botulinum toxin was moreeffective in patients who were not using a concurrent headacheprophylaxis treatment (i.e. BOTOX monotherapy) regardless of anymedication overuse issue.

Additionally, the same study showed (see FIGS. 8 and 9) that a botulinumtoxin was more effective in the patients who were not using a concurrentheadache prophylaxis treatment (“without prophylaxis”) (i.e. a botulinumtoxin [i.e. BOTOX monotherapy) and were overusing medication (i.e. “MOU”patients). This is a discovery in addition to our discovery that abotulinum toxin can be used to treat headache in a patient overusingacute medication, without regard to the fact that the patient is beingtreated with a botulinum toxin monotherapy or that he or she is beingtreated for headache with other headache prophylaxis medications.

Furthermore, with regard to acute medication use in patients (notoveruse, but any use) the study showed that treatment of headache with abotulinum toxin resulted in a significant decrease in use of narcoticsby these patients (see eg day 210 in FIG. 10).

Finally, and significantly the study also showed (see FIGS. 11 and 12)that after treatment with a botulinum toxin (such as BOTOX) there was agreater decrease in the frequency of headache and as well in the numberof days acute analgesic medications were required in the patients whowere overusing triptans headache medication at baseline (i.e. upon studyinitiation), as compared to the patients who were not overusing triptanmedications. This indicates that triptans are more effective to treatheadache when used in conjunction with a botulinum toxin. Thus a methodfor increasing the effectiveness of a triptan to treat a headache can becarried out by using a triptan and a botulinum toxin concurrently totreat a headache.

As is well known, triptans don't prevent headaches from occurring.Instead they act only to treat the pain associated with a headache thata patient is currently experiencing. See eg Gladstone J P., et al.,Newer formulations of the triptans: advances in migraine management,Drugs. 2003; 63(21):2285-305. Clinically, triptan medication overuseappears to actually cause or to exacerbate headache pain, as opposed tothe alleviation of headache pain which can result from normal triptanuse. See eg Relja G., et al., Headache induced by chronic substance use:analysis of medication overused and minimum dose required to induceheadache, Headache. 2004 February; 44(2):148-53. Therefore, it was asurprising discovery, as set forth by FIGS. 11 and 12, for us to findthat administration of a botulinum toxin helps to prevent headaches in apatient population who have headaches, more frequent headaches orexacerbated headaches due to triptan medication overuse. This discoveryis demonstrated by study results and patient observations showing thattriptan MOU patients needed less triptan medication after botulinumtoxin administration.

Detailed Study Description

The study carried out was a multicenter, double-blind, randomized,placebo-controlled, parallel group study of multiple treatments ofBOTOX® (botulinum toxin type A purified neurotoxin complex) for theprophylactic treatment of headaches in a chronic headache population.

ABBREVIATIONS AND DEFINITION OF TERMS

-   AGN 191622 Botulinum Toxin, Type A Purified Neurotoxin Complex-   ANOVA Analysis of variance-   ANCOVA Analysis of covariance-   ATC Anatomical-Therapeutic-Chemical drug thesaurus-   Baseline period First 30-day period during which patient enter the    screening period (Day −60 to Day −30)-   BOTOX® BOTOX® (Botulinum Toxin Type A) Purified Neurotoxin Complex-   bpm Beats per minute-   CDH Chronic daily headache-   CFR Code of Federal Regulations-   CGRP Calcitonin gene-related peptide-   COSTART Coding symbols for thesaurus of adverse reaction terms-   CRF Case report form-   CSR Clinical study report-   CTTH Chronic tension type headache-   FDA United States Food and Drug Administration-   GCP Good Clinical Practice-   GLP Good Laboratory Practice-   HCG Human chorionic gonadotropin-   HIQ Headache Impact Questionnaire-   Hemicrania continua Rare, indomethacin-responsive headache disorder    characterized by a continuous but fluctuating, moderately-severe,    unilateral headache-   HPSQOL Headache Pain Specific Quality of Life Questionnaire-   ICHD International Classification of Headache Disorders-   IEC Independent Ethics Committee-   IHS International Headache Society-   IVRS Interactive Voice Response System-   IRB Institutional Review Board-   LD₅₀ Calculated median lethal dose-   MIDAS Migraine Disability Assessment-   Month 30 day period-   MS-QOL Migraine-Specific Measure of Quality of Life-   NA Not available; not applicable-   New daily persistent headache Acute onset of constant unremitting    headache with no history of CTTH or migraine-   NOS Not otherwise specified-   NSAIDs Nonsteroidal anti-inflammatory drugs-   QOL Quality of life-   RBC Red blood cell-   Run-in period Day −30 to Day −1, when all patients received placebo    treatment-   SD Standard deviation-   SGOT Serum glutamic-oxaloacetic transaminase-   SGPT Serum glutamic-pyruvic transaminase-   Transformed Migraine Chronic daily headache evolving from episodic    migraine-   Treatment 1 Visit at which patients received injection of placebo    and entered the placebo run-in, also called Day −30 (Visit 2)-   Treatment 2 Visit at which patients were randomized to receive    either BOTOX® or placebo, also called Day 0 (Visit 3)-   Treatment 3 Visit at which patients received either second treatment    of BOTOX® or third treatment of placebo, also called Day 90 (Visit    6)-   Treatment 4 Visit at which patients received either third treatment    of BOTOX® or fourth treatment of placebo, also called Day 180 (Visit    9)-   U Unit (1 U corresponds to the calculated median lethal    intraperitoneal dose [LD₅₀] in mice)-   WBC White blood cell-   WHO World Health Organization

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This was a multicenter study, with investigators at 13 U.S. sites.Headache is probably the most common neurological symptom in clinicalpractice (Castillo et al, 1999). In the United States in 1 year, most ofthe population will have a headache and over 5% will seek medical aid(Silberstein and Silberstein, 1990). Headaches can be either episodic(less than or equal to 15 headache days per month) or chronic (greaterthan 15 headache days per month) (Silberstein and Lipton, 2001).Recurrent headaches are symptoms of a chronic primary headache disorder.

Chronic daily headache (CDH) is a heterogeneous disorder, affecting 4%to 5% of the general population (Castillo et al, 1999; Scher et al,1998; Wang et al 2000). Chronic daily headache is the most commonheadache seen in headache specialty clinics (Silberstein et al, 1994).Although not included in the International Headache Society (IHS)classification (Headache Classification Subcommittee of theInternational Headache Society, 1988, revised 2004), the concept of CDHis well recognized (Silberstein and Lipton, 2000). Some investigatorshave suggested a revision of the IHS classification to include a definedCDH entity (Manzoni et al, 1995; Silberstein et al, 1994).

More than 90% of CDH patients initially report episodic headaches(Silberstein and Lipton, 2000). Patients in whom episodic migraines haveprogressed into chronic daily headache are described as having“transformed migraine” (Silberstein et al, 1994). Mathew et al (1987)reported that patients with CDH who evolved from initially episodicmigraine differed from patients with episodic headaches alone regardingabnormal personality profile, elevated depression scores, identifiablestress, medication overuse and hypertension. Most patients with CDHreport their role functioning and well-being as frequently and severelyimpaired (Holroyd et al, 2000), highlighting the importance of thisgroup of headaches on quality of life (Monzon and Lainez, 1998; Wang etal, 2001). Very few studies have evaluated headache prophylactictreatment in patients with CDH (Saper et al, 2002; Slivestrini et al,2003; Spira et al, 2003). To date, no drug has received regulatoryauthority approval for the prophylaxis of headaches in migraine patientswith CDH. There appears to be an unmet medical need in this debilitatedpatient population.

BOTOX® therapy has been reported to alleviate pain associated withvarious conditions with or without concomitant excess musclecontractions (Aoki, 2001). This includes cervical dystonia (Brin et al,1987), spasticity (Wissel et al, 2000), tension-associated headache(Smuts et al, 1999), chronic whiplash-associated neck pain (Freund andSchwartz, 2002), myofascial pain (Cheshire et al, 1994), migraineprophylaxis (Blumenfeld et al, 2004), and back pain (Foster et al,2001). The toxin is known to inhibit the release of theneurotransmitter, acetylcholine, at the neuromuscular junction, therebyinhibiting striated muscle contractions. In the majority of painsyndromes where BOTOX® has been studied, inhibiting muscle spasms is animportant component of its activity. However, the reduction of painoften occurs before the decrease in muscle contractions suggesting thatBOTOX® has a more complex mechanism of action than initiallyhypothesized (Aoki, 2003). Data has been published which suggests apain-reducing effect of BOTOX® separate from its neuromuscular activity.BOTOX® appears to act both peripherally (directly) and centrally(indirectly) on sensory nerves. The hypothesis that BOTOX® mediates anantinociceptive activity peripherally is supported by its inhibition ofneurotransmitters such as glutamate (Cui et al, 2004), CGRP (calcitoningene-related peptide) (Purkiss et al, 2000; Welch et al, 2000), andsubstance P (Durham et al, 2004). An indirect reduction of centralsensitization is supported by studies investigating the stimulation ofthe immediate early gene, c-fos, using the formalin-challenged ratmodel. In these studies activation of the c-fos gene and expression ofits protein product, Fos, indicate rapid neuronal firing in response tostimuli. BOTOX® treatment reduced Fos expression after formalinchallenge in a dose-dependent manner indicating an indirect centraleffect in reducing pain (Cui et al, 2004).

The objective of this study was to evaluate the safety and efficacy ofmultiple treatments of BOTOX® compared with placebo for the prophylactictreatment of headaches in the chronic headache population.

This was a multicenter, double-blind, randomized, placebo-controlled,parallel-group clinical study of multiple treatments of BOTOX® comparedwith placebo in the management of patients with chronic daily headache.The overall duration of the study for each patient was 11 months.Patients were screened at Day −60 (baseline period). During this perioddata were collected daily from the patient regarding specifiedcharacteristics of their headache episodes and headache medication usefor 30 days using electronic telephone diaries. Following the baselineperiod, patients returned at Day −30 (Treatment 1) for the placeborun-in period. At this visit, patients meeting the inclusion/exclusioncriteria were injected with single-masked placebo, and again recordedspecified characteristics of their headache episodes for 30 days usingelectronic diaries. Treatment 1 injections were in a minimum of 6 muscleareas and 23 to 58 injection sites within these areas as specified inTable 9.4.1 and Figure 9.4.1 (see Section 9.4.1), dependent upon thelocation and severity of pain. The investigator also had the option toinject the masseter if the patient was experiencing pain in that muscle.

After 30 days (at Day 0) patients returned to be randomized forTreatment 2. Prior to randomization, using diary information collectedduring the placebo run-in period, patients were classified as a placeboresponder if they had <16 headache days or had a ≧30% decrease frombaseline in the frequency of headache days. All other patients wereconsidered placebo non-responders. Patients within each stratum(responders, non-responders) were randomized to receive either BOTOX® orplacebo at Day 0 (Treatment 2).

Patients received additional treatments at Day 90 (Treatment 3) and Day180 (Treatment 4). Patients returned for follow-up visits at 30-dayintervals following each treatment through Day 270. If a patient exitedthe study at any visit prior to Day 270 (exit), all exit procedures andevaluations were to be completed at that visit. For Treatments 2, 3, and4, patients were injected with BOTOX® or placebo using the same dose andvolume and in the same muscle areas and sites as in Treatment 1. Theschedule of study visits and measurements is shown in Table 2.

The study design included the recognized elements of a well-controlledclinical trial that are necessary for an unbiased evaluation of thetreatment effect. The study was randomized and double-blind to minimizeinvestigator and patient bias. Blinding was ensured by the similarity inappearance of the vials of study medication and requiring that anindividual at each study center who had no other study involvementreconstituted the study medication and filled the syringes forinjection. A placebo-controlled, parallel-group design eliminatedpossible confounding effects that are inherent in other study designs.The design of this study generally conformed to the recommendations ofthe International Headache Society (IHS) for studies in the prophylactictreatment of migraine (IHS Committee on Clinical Trials in Migraine,1991).

The present study was conducted to assess the potential benefit ofBOTOX® in headache prophylaxis in the adult chronic daily headachepopulation. The term chronic daily or chronic near-daily headache hasbeen used to refer to very frequent headaches (i.e., 16 or more headachedays a month) not related to a structural or systemic illness(Silberstein and Lipton, 2001). The key requirement for entry into thecurrent study was primary headache disorder with 16 headache days permonth by history and confirmed by electronic diary during baseline.Headache disorder could include any combination of episodic/chronictension-type headaches, migraines with or without aura, and/ormigrainous headaches (as defined by IHS criteria [HeadacheClassification Subcommittee of the IHS, 1988, revised 2004], and/orchronic daily headache as defined by Silberstein and Lipton, 2001).

In contrast to the fixed site/fixed dosage treatment approach used inprevious clinical studies in the episodic migraine population,physicians participating in this study were allowed to use a moreindividualized or patient-tailored treatment approach depending on thelocation of the patient's head pain. Specifically, physicians were giventhe opportunity determine the number of injection sites and the dosagewithin a protocol-specified range to be administered for the specifiedfrontal and posterior muscle areas of the head and neck, depending onthe location and severity of a patient's headache. Maximum dose levelsallowed in this study also were higher than those used in previousstudies due to the addition of injection of larger, posteriorpericranial and neck muscles.

Due to the high placebo response rate seen in the previous studies, aplacebo run-in period was implemented in the present study to stratifypatients into 2 groups (placebo responders and placebo non-responders).During the placebo run-in period patients were not informed as towhether they were injected with BOTOX® or placebo. Furthermore, thestudy protocol was amended to include 3 double-blinded treatment cyclessince, based on clinicians' clinical experience multiple treatments areneeded to demonstrate benefit from this treatment. Treatment of otherconditions such as spasticity and glabellar lines have shown anincreased benefit in patients upon repeated injections with BOTOX®. Inaddition, it was anticipated that the placebo response would stabilizeor diminish over time and multiple treatments.

Efficacy criteria were as follows. For the primary variable, adifference of 3 headache-free days between BOTOX® and placebo in themean change from baseline in the frequency of headache-free days permonth at Day 180 was considered clinically significant.

Injections and evaluations were to be performed by the same investigatorthroughout the study whenever possible. If it was not possible to usethe same investigator to follow a given patient, then injections andevaluations were to overlap between the investigators for at least 1visit whenever possible.

The clinical hypotheses for this study were that BOTOX® was moreeffective than placebo, as measured by the difference between groups inthe change from baseline in the frequency of headache-free days permonth, and that BOTOX® had an acceptable safety profile.

In this study several additional supplemental analyses were conductedafter database lock to further understand and evaluate the effects ofBOTOX® treatment. Many of these analyses were based on the updatedinformation on the classification of headaches and a betterunderstanding/definition of concomitant medications used by headachepatients provided in the International Classification of HeadacheDisorders (ICHD) (Headache Classification Subcommittee of the IHS,2004).

All patients enrolled in this study met at least the following inclusioncriteria:

-   -   Male or female, 18 to 65 years old    -   Primary headache disorder with ≧16 headache days per month by        history and confirmed by diary during baseline, which could        include any combination of migraines with or without aura,        episodic/chronic tension-type headaches, and/or migrainous        headaches (as defined by 1988 IHS criteria) (Headache        Classification Subcommittee of the IHS, 1988)    -   Willing and able to give written informed consent    -   Stable medical condition    -   Stable chronic medications, if any, including non-acute,        prophylactic migraine medications, for at least 3 months        immediately prior to Day −60    -   Willing and able to stay on current medications during the        course of the study    -   Willing and able to complete the entire course of the study and        to comply with study instructions, including diary phone system.

The patients included in this study were suitable for the study purposesas their diagnosis met the definition of headache as outlined by the IHS(Headache Classification Committee of the IHS, 1988) and their baselineheadache characteristics were sufficient to detect a change followingtreatment.

A dose range of units to be injected into each muscle area was defined,except for the occipitalis muscle where the dosage was fixed. The numberof injection sites (total of 23 to 58 injection sites) within eachspecified muscle area (6 to 7 muscle areas) and dose injected (105 U to260 U) was determined by the physician based on the pain distributionpattern and the severity of pain in the particular muscle area. Patientswere to be injected in a minimum of 6 muscle areas, which included thefrontal/glabellar, occipitalis, temporalis, semispinalis, spleniuscapitis, and trapezius muscles, as specified in Table 1 and FIG. 13. Itwas optional to inject the masseter muscle. Patients were to be injectedwith the same dose and in the same muscle areas and sites for treatments1, 2, 3, and 4. Whenever possible, treatments for each patient were tobe performed by the same physician throughout the study.

TABLE 1 Study Medication Dose and Injection Sites Number of BilateralTotal Muscle Area Units ^(a) Injection Dose (U) Frontal/Glabellar 25-40No 25-40 Occipitalis 10 Yes 20 Temporalis 10-25 Yes 20-50 Masseter(optional)  0-25 Yes  0-50 Trapezius 10-30 Yes 20-60 Semispinalis  5-10Yes 10-20 Splenius capitis  5-10 Yes 10-20 Total Dose Range 105-260Note: Patients were injected with BOTOX ® or placebo in the specifiedmuscles with doses determined by the investigator. ^(a) Patientsrandomized to the placebo group received 0 U of BOTOX ®.

Each vial of BOTOX® (Allergan, Irvine, Calif.) contained 100 U ofClostridium botulinum toxin type A, 0.5 mg albumin (human), and 0.9 mgsodium chloride in a sterile, vacuum-dried form without a preservative.One U corresponds to the calculated median lethal intraperitoneal dose(LD₅₀) in mice. Each vial of placebo contained 0.9 mg sodium chloride ina sterile, vacuum-dried form without a preservative.

The vials were stored in a freezer between −20° C. and −5° C. beforeuse. Directions for reconstitution with the diluent, 0.9% sterile saline(without preservatives), for injection were provided in the protocol.Each vial of BOTOX® or placebo was reconstituted with 2.0 mL of salineper vial for a concentration of 50 U/mL. An individual with no otherstudy involvement reconstituted the study medication and filled thesyringes. Reconstituted study medication that was not used immediatelywas to be stored in a refrigerator (2° C. to 8° C.) for no more than 4hours.

A screening number was assigned to each patient at Day −60 to be used aspatient identification for the electronic diary and on all documentationuntil Day 0. At Day 0, following the placebo run-in period, patientswere classified as placebo responders if they reported <16 headache daysor a ≧30% decrease in the frequency of headache days based on the diaryinformation collected during the placebo run-in period. All otherpatients were classified as placebo non-responders. Using a stratifiedrandomization, patients were then randomized within each stratum(placebo non-responder or placebo responder) to Treatment 2 (BOTOX® orplacebo). The patient number assigned at Day 0 was provided to the sitevia a central validated Interactive Voice Response System (IVRS)randomization. This patient number was used on all subsequentdocumentation.

Randomization schedules were generated by using procedures developed andvalidated at Allergan (PLAN procedure in SAS® software, version 8.2).Patients were randomized to receive BOTOX® or placebo in a ratio of 1:1in blocks of 4.

The randomization number assigned the patient to receive either BOTOX®(not a specific dose level) or placebo. The independent staff person(who did not know the identity of the treatment) reconstituted 3 vialsof study medication and drew the study drug into the syringes foradministration, even if the total dose for a patient was only going torequire 2 vials. The syringes were then given to the investigator forinjection.

In this study, in contrast to the fixed site/fixed dosage treatmentapproach used in previous studies, physicians were allowed to use a moreindividualized or patient-tailored treatment approach. Specifically, thenumber of injection sites (23 to 58 injection sites) within eachspecified muscle area (6 to 7 muscle areas) and dose injected (totaldose of 105 to 260 U) was determined by the physician based on thepatient's usual pain distribution pattern and the severity of pain inthe particular muscle area. Total dose levels used were higher thanthose used in previous studies since more units were injected andadditional muscles were added (posterior pericranial and neck musclestrapezius, semispinalis, and splenius capitis muscles). Such an approachwas anticipated to more closely approximate what is reported in clinicalpractice. The choice of the higher doses used in this study was furthersupported by the results of earlier studies in which BOTOX® at doses ofup to 360 U was found to be safe and effective in the treatment ofpatients with cervical dystonia.

As this study was ongoing information gathered from clinical experts andreports within the literature (eg, Troost 2004) pointed to the fact thatit may take several treatment cycles to observe the clinical benefit ofBOTOX®. With this in mind, the protocols were amended to include a totalof 3 treatment cycles (following the placebo run-in) and the primaryendpoint was changed to Day 180 in the placebo non-responder stratum. Bythe time these amendments were put in place, a significant number ofsubjects had exited the original study at the planned Day 120 timepoint. Therefore, enrollment was extended to ensure that at least 90placebo non-responder patients (45 per treatment group) were availablefor the Day 180 analysis.

Based on the learnings of the early Phase 2 studies it was thought thata dosing interval of every 4 months may be too long. Additionally,treatment intervals of 3 months for other BOTOX® muscle-relatedindications has been shown to be optimal. Therefore, in the currentstudies the treatment cycles were shortened to every 3 months. A totalof 3 double-blind treatment cycles were included because, based onphysicians' clinical experience, it was anticipated that multipletreatments would be needed to demonstrate benefit for this treatment.This hypothesis was supported by spasticity studies and glabellar linesstudies in which an increased benefit was observed in patients uponrepeated injections with BOTOX®.

The placebo run-in was a single-masked treatment whereby theinvestigator, but not the patient, knew that the treatment administeredwas to be placebo. Starting at Day 0, this was a double-blind study andneither the investigator nor the patient was to know which treatment wasto be administered at Day 0, Day 90, and Day 180. To maintain thisblinding, an individual, with no other study responsibilities,reconstituted the study medication and filled the syringes forinjection. Treatment blinding was also protected by not describing therandomization block size for the study.

If necessary for the safety and proper treatment of the patient, theinvestigator could have unblinded the patient's treatment assignment todetermine which treatment the patient had received and instituteappropriate follow-up care.

The use of any concurrent medication (eg, prescription orover-the-counter, including herbal remedies) was recorded on thepatient's CRF along with the reason the medication was taken. Inaddition, medications that the patient had taken for treatment of his orher headaches since 7 days prior to Day −60 were recorded on theappropriate medication CRF. During the study, the patient was to reportany use of concomitant medication for headache treatment using theelectronic telephone daily diary.

Patients taking concurrent therapies were to maintain a stable dose anddose regimen during the study, particularly with regard to the use ofnon-acute, prophylactic migraine medications. Medications that wereconsidered necessary for the patient's welfare could be given at thediscretion of the investigator. The administration of all medicationswas to be reported on the CRFs.

During the course of the study, patients were not to take or receiveaminoglycoside antibiotics, cholinergic antagonists, curare-like agents,or agents that might interfere with neuromuscular function. Theoccasional use of muscle relaxants was permissible at the discretion ofthe investigator. However, patients were not to take muscle relaxants ona chronic basis in the 3 months prior to study entry and/or during thestudy. Lastly, patients were not to change their chronic medicationsduring the study unless it was medically necessary.

The decision to administer a prohibited medication/treatment was to bedone with the safety of the study participant as the primaryconsideration. The investigator administered study medication to eachpatient by intramuscular injection.

Efficacy Measures

Efficacy measures were variables derived from information recorded bypatients for the duration of the study using a validated electronicheadache diary using a telephone interactive voice response system(IVRS) and the patient's global assessment of response to treatmentobtained from CRFs. Electronic diaries were to be completed on a dailybasis throughout the study. Patients recorded start/stop times ofheadaches, maximum and average severity of headaches, location and typeof headache pain, effect on physical activity, presence of aura,presence of associated symptoms of headaches (nausea, vomiting,photo/phonophobia), and headache medications and doses used.

The primary efficacy measure was the change from baseline in thefrequency of headache-free days in a 30-day period. The primary visitfor determination of efficacy was Day 180, with the evaluationreflecting the prior 30-day period. Baseline for the efficacy measureswas defined as the frequency of headache-free days during the first30-days of the screening period. A difference of 3 headache-free daysbetween BOTOX® and placebo in the mean change from baseline in thefrequency of headache-free days per 30-day period at Day 180 wasconsidered clinically significant.

The secondary efficacy measure was the proportion of patients with adecrease from baseline of 50% or more in the frequency of headache daysper 30-day period at Day 180.

Other efficacy variables included the following:

-   -   proportion of patients with a decrease from baseline of 50% or        more in the frequency of headaches per 30-day period    -   frequency of headaches of any severity (per 30-day period)    -   frequency of migraine headaches of any severity (per 30-day        period)    -   proportion of patients with a decrease from baseline of 50% or        more in the frequency of migraine headaches per 30-day period    -   proportion of patients with a decrease from baseline of 2 or        more migraine headaches per 30-day period    -   moderate to severe migraine headache frequency (per 30-day        period)    -   patient's global assessment of response to treatment from        baseline, as follows:        -   −4=very marked worsening (about 100% worse or greater)        -   −3=marked worsening (about 75% worse)        -   −2=moderate worsening (about 50% worse)        -   −1=slight worsening (about 25% worse)        -   0=unchanged        -   +1=slight improvement (about 25% improvement)        -   +2=moderate improvement (about 50% improvement)        -   +3=marked improvement (about 75% improvement)        -   +4=clearance of signs and symptoms (about 100% improvement)    -   number of days per 30-day period with non-migraine headaches    -   maximum and average headache severity (none, mild, moderate,        severe)    -   number of days that acute headache medication was used during        the study    -   number of uses (intakes) of acute headache mediation during the        study

Other Variables Included the Following:

Treatment Assessment Questionnaire:

This questionnaire was designed to collect information from the patientsregarding the treatment they thought they had received (BOTOX® orplacebo). The questionnaire was administered on Day 90 (asking patientsto indicate what treatment they thought they had received at Day-30 andat Day 0), Day 180 (asking patients to indicate what treatment theythought they had received at Day 90), and Day 270 or when patientsexited the study (asking patients to indicate what treatment theythought they had received at Day-180).

Pain Diagram:

Patients completed a pain diagram at baseline and exit to illustrate themuscle areas where their headache originated and where it ended.

Headache Count Recall:

Patients reported how many headaches they thought they had experiencedin the last 30 days at every visit starting at Day 30. This informationwas to be used as backup data in the event that the electronic diarydata were unavailable.

Health Outcomes Measures:

The questionnaires were given to patients to complete in as quiet anarea as possible prior to any queries regarding their health orcondition and prior to any study procedures being performed. Patientswere instructed to initial and date the last page of each questionnairein the space provided at the time of completion. Study site personnelreviewed the questionnaires to assure completeness and requested thatpatients complete any unanswered questions if unintentionally leftblank.

Migraine Disability Assessment (MIDAS)

The MIDAS was administered at Days −60, 90, 180 and 270. Thequestionnaire collected information on the effect of headaches onproductivity and activity over the previous 3-month period.

Headache Pain-Specific Quality of Life Questionnaire

This questionnaire was administered at Days −60, 0, 90, 180 and 270.This series of questions was originally adapted from the MedicalOutcomes Trust Patient Assessment Questionnaire (Stewart et al, 1992).These questions previously have been used with migraine patients(referring to pain, not migraine pain specifically) to assess how muchpain interfered with four domains of a patient's life (i.e., dailyactivities, emotional health, physical health, and work) over a 4-weekperiod (Solomon et al, 1995). The questions were measured on a 5-pointscale (not at all, a little, moderately, quite a bit, extremely).

SF-36 Health Survey

This survey was administered at Days −60, 0, 90, 180 and 270. The SF-36is a general health-related quality of life questionnaire, containing 8domains; Physical Functioning, Role Physical, Bodily Pain, GeneralHealth, Vitality, Social Functioning, Role Emotional, and Mental Health.The SF-36 may be reported using the domains or the 2 summary scales(Physical Component Scale and Mental Component Scale).

Headache Impact Questionnaire (HIQ)

The HIQ Version 3.0.1 is designed to collect information from patientson how their migraines may affect various aspects of their life. Datawere collected in 2 sections:

Resource Utilization:

Patients reported the frequency of resources utilized due to migrainesymptoms and treatments (eg, frequency of doctor visits, emergency roomvisits, and hospitalization). Resource utilization was assessed at Day−60 only.

Patient Satisfaction:

Patients rated their satisfaction with various aspects of treatment(i.e., overall effectiveness of acute and prophylactic medications,effect of treatments on frequency and severity of symptoms, ability toavoid and manage symptoms, and amount spent on treatments) on a 5-pointscale (very satisfied, somewhat satisfied, neutral, somewhatdissatisfied, very dissatisfied). Satisfaction was assessed at Days −60,0, 90, 180, and 270 or exit.

Primary Chronic Daily Headache Assessment:

On Day 180, the investigator indicated the predominant diagnosis for thepatient by choosing 1 of 4 types of primary chronic daily headacheexperienced by the patient (i.e., transformed migraine, chronictension-type headache, new daily persistent headache, hemicraniacontinua) using the Silberstein diagnostic criteria for chronic dailyheadache subtypes (Silberstein and Lipton, 2001).

Schedule of Assessments

The frequency and timing of study visits and measurements are outlinedin Table 2. Additional examinations were performed as necessary toensure the safety and well-being of patients during the study.

TABLE 2 Schedule of Assessments Visit 9 Visit 2 Visit 3 Visit 6 (Treat-Visit 1 (Placebo (Randomi- (Treat- ment Visit Visit Visit 12 (BaselineRun-In/Treat- zation/Treat- ment Visit 7 Visit 8 4) 10 11 (Exit) Period)ment 1) ment 2) Visit 4 Visit 5 3) Day Day Day Day Day Day Day −60 Day−30 Day 0 Day 30 Day 60 Day 90 120 150 180 210 240 270 View Video/Obtain✓ Informed Consent Inclusion/Exclusion ✓ ✓ ✓ Criteria Review Medical and✓ ✓ ✓ Medication History Physical Examination ✓ ✓ Vital Signs ✓ ✓ ✓ ✓ ✓✓ ✓ ✓ ✓ ✓ ✓ ✓ Headache Diary ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ Instructions andReview Injection of Study ✓ ✓ ✓ ✓ Medication Patient Global ✓ ✓ ✓ ✓ ✓ ✓✓ ✓ ✓ ✓ Assessment Pain Diagram ✓ ✓ Headache Count Recall ✓ ✓ ✓ ✓ ✓ ✓ ✓✓ ✓ Beck Depression ✓ Inventory Primary Chronic Headache ✓ AssessmentTreatment Assessment ✓ ✓ ✓ Questionnaire MIDAS ✓ ✓ ✓ ✓ Headache-PainSpecific ✓ ✓ ✓ ✓ ✓ Quality of Life Questionnaire Headache Impact ✓ ✓ ✓ ✓✓ Questionnaire SF-36 Health Survey ✓ ✓ ✓ ✓ ✓ Medical Events ✓ ✓ ✓Adverse Events ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ Toxin Neutralizing ✓ ✓ ✓ ✓ AntibodyTiter Blood Draw CBC/Blood Chemistry ✓ ✓ Urine Pregnancy Test ✓ ✓ ✓ ✓ ✓Menstrual Cycle Data ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓

Appropriateness of Measurements

The efficacy measurements used in this study have been utilized in otherstudies of headache prophylaxis treatments (including BOTOX®) and wereconsidered to be appropriate for this study in CDH patients. Theassessment of safety by adverse events, vital signs, and clinicallaboratory tests is standard practice in Phase 2 studies.

Primary Efficacy Variable(s)

The primary endpoint was the change from baseline in the frequency ofheadache-free days in a 30-day period the placebo non-responder stratumDay 180.

Statistical Analysis

The “as-treated” population for both the safety and efficacy analysesincluded all patients treated with the second injection at Day 0(randomization/Treatment 2), regardless of subsequent injections. Forcomparisons of all variables, patients who were randomized and treatedwere analyzed according to the treatment they received at the secondinjection (i.e., Day 0/Treatment 2). They were analyzed in theresponder/non-responder stratum indicated by baseline and placebo run-indata, regardless of which stratum they were assigned to duringrandomization.

The primary efficacy variable was the change in the frequency ofheadache-free days from a 30-day baseline period (Day −60 to Day −31).Headache-free days in each 30-day period were determined from datarecorded in the telephone electronic diary. Data recorded in the diariesincluded headache start date and time and headache stop date and time,and the following headache characteristics: usual headache pain (mild,moderate, severe); worst headache pain (mild, moderate, severe); side ofthe head (unilateral/bilateral); type of pain (pulsating/throbbing orpressing/squeezing); and effect of physical activity on pain (worse, notworse). It also included headache symptoms: aura (yes or no);interference of activities (yes or no); and other symptoms (nausea,vomiting, sensitivity to light [photophobia], sensitivity to noise[phonophobia]). The diary data also included acute medication taken forthe headache (yes or no) and the name and dose of the medication.

A headache episode was determined by the recording in the diary ofheadache start and/or stop times and/or headache characteristics,headache symptoms and/or medications taken for headaches. To calculatethe duration of headaches, missing start and/or stop times wereestimated as follows:

-   -   If a start time was recorded with no corresponding stop time,        the stop time was set as 6 AM the following day, following the        last contiguous recording of any headache characteristics,        headache symptoms, or use of headache medication.    -   If a stop time was recorded with no corresponding start time,        the start time was set as 6 AM the same day. If the stop time        preceded the start time (i.e., stop time before 6 AM), the stop        date was reset to the day after the start date.    -   If a headache was recorded with neither a start time nor a stop        time, the start and stop times were set according to the        preceding 2 rules. Such a headache was indicated by the        recording of any of the headache characteristics, headache        symptoms, or use of headache medications.

For migraine headaches, an overriding rule was that if for 2 consecutivemigraine headaches there was less than 24 hours between the stop time ofthe first headache and the start time of the second headache, they wereconsidered to be 1 continuous migraine headache.

A headache day was defined as the occurrence of a headache episode inthe 24-hour period from midnight (inclusive) at the start of the day tomidnight (not inclusive) at the end of the day, and did not depend onthe frequency of headache episodes during that day. The counting ofheadache days (and thus, headache-free days) was done independent of theabove 24-hour rule for migraines.

A headache-free day was defined as a day that was not a headache day. Ifa continuing patient had diary data for a given day that was missing andremained missing after implementation of the missing headache time rulesgiven above, it was assumed to be a headache-free day. If a patientrecorded diary data at least 10 days but less than 30 days into a 30-daystudy period, the frequency of headache-free days for the 30-day periodwas prorated accordingly and rounded to a whole number. For example, ifa patient's ‘baseline’ period was 26 days, the frequency ofheadache-free days was multiplied by 30/26. If a patient's recordeddiary data extended less than 10 days into a 30-day period, the patientwas not included in the summary tables for that 30-day period. If thebaseline period between the screening visit and the placebo run-ininjection exceeded 30 days, the baseline period only included the first30 days. The same conventions applied to other 30-day periods.

The primary efficacy variable was the change from baseline in thefrequency of headache-free days in a 30-day period. The primaryassessment time was Day 180. The primary interest was in the comparisonof BOTOX® and placebo in the non-responder stratum. The primary analysisused “observed” data, as modified by the above missing headache timerules and rules for prorating the frequency of headache days.

The primary null hypothesis was that BOTOX® treatment and placebo wereequally effective as measured by the change in frequency ofheadache-free days in the 30-day period ending at Day 180 in thenon-responder stratum. The 2-sided alternative hypothesis was thatBOTOX® and placebo were not equally effective. Analogous hypothesesapplied to other efficacy variables.

All hypothesis tests were 2-sided. For the interim analysis at Day 90,statistical significance for the primary variable was declared only fora p-value <0.005. Multiple comparison adjustments were made by using theO'Brien-Fleming group sequential method to set the significance level at0.048 for the primary analysis at Day 180. No adjustments formultiplicity were made for the exploratory final analysis at Day 270.All other hypothesis tests used a type-I error of alpha=0.05 todetermine statistical significance, except that treatment-by-subgroupinteractions were examined at the 0.10 level.

For the frequency of headache-free days at baseline and its change frombaseline in the non-responder stratum, comparisons between treatmentgroups were done with the Wilcoxon rank-sum test (Siegel, 1956). Ifthere had been significant baseline differences between treatments inthe primary variable, the baseline value of the variable would have beenincluded as a covariate in an analysis of covariance of the ranks of thevariable.

To justify the pooling of data over multiple clinical sites, anexamination was made of treatment-by-clinical site interaction effectsin the analysis of the primary efficacy variable (change from baselinein the frequency of headache-free days per 30-day period). This analysiswas performed using an analysis of variance (with type III sums ofsquares) modeling response as a function of clinical site, treatment,and their interaction. In this analysis, clinical sites were pooled (asa pseudo center) if they had fewer than 6 patients in either of theresponder or non-responder stratum for the final 30-day period of theanalysis (Days 90, 180 or 270). All small centers were pooled regardlessof the size of the resulting pooled center. However, in some of theexploratory supplemental by-investigator tables, small centers wereexcluded from analysis.

Similar analyses to evaluate treatment-by-subgroup interactions wereperformed for age, gender, race, time since disease onset, chronic dailyheadache subtype, baseline menstrual headache, baseline MIDAS total daysscore, baseline prophylactic treatment, baseline beta blocker use,baseline calcium channel blocker use, baseline anticonvulsant use, andbaseline antidepressant use.

Comparison of the treatment groups in the responder stratum was asecondary objective of the analysis. Supplemental analyses includedanalyses of data pooled across strata, and with and without concomitantheadache prophylaxis treatment.

Secondary endpoints included the changes from baseline to other timepoints (Days 30, 60, 90, 120, 150, 210, 240, and 270) in the frequencyof headache-free days per 30-day period in each stratum. The statisticalmethods used to analyze these other time points were the same as for theprimary time point.

In addition to the “observed cases” analyses, supplemental analyses wereperformed using imputed data for missing values. Detailed methodologyregarding how missing data were imputed is included in Section 5.3.1 ofthe analyses plan (Appendix 16.1.9).

There was 1 secondary efficacy variable to be summarized for each 30-daydiary period associated with each visit, namely, the proportion ofpatients with a decrease from baseline of 50% or more headache days per30-day period for the placebo non-responder stratum at Day 180. Thisvariable was analyzed using the observed data with Pearson's chi squaretest. For this secondary efficacy variable, as for the primary variable,supplemental analyses using imputed data for missing values wereperformed. Comparison of the treatment groups in the responder stratumwas a secondary objective of the analysis. Supplemental analysesincluded analyses of data pooled across strata, and subgroup bytreatment interaction, including with and without concomitant headacheprophylaxis treatment.

Other continuous protocol-specified efficacy variables to be summarizedfor each 30-day period included the following: frequency of headaches ofany severity, frequency of migraine headaches of any severity, frequencyof moderate to severe migraine headaches (as determined by the “worst”headache severity rather than the “usual” headache severity), worstheadache severity (mild, moderate severe), usual headache severity(mild, moderate severe), number of days with non-migraine headaches,number of days with use of acute analgesic headache medication, andpatient's global assessment of response to treatment. The change frombaseline for continuous variables was analyzed as described for ordinalvariables.

Analyses also were performed for the following protocol-specifiedefficacy variables for each 30-day period: proportion of patients with adecrease from baseline of 50% or more headaches, proportion of patientswith a decrease from baseline of 50% or more migraine headaches, andproportion of patients with a decrease from baseline of 2 or moremigraine headaches. As in the analysis of a decrease from baseline of atleast 50% in the frequency of headaches, separate analyses also wereperformed for decreases of 30%, 40%, 60%, 70%, 80%, 90% and 100% forheadaches, headache day, migraines, and moderate or worse migraines.

In addition, analyses were performed of the proportions of patients witha sustained 50% decrease from baseline in the frequency of headachedays. Within a treatment cycle, a patient was considered to be asustained responder if the patient had at least a 50% decrease during 2consecutive 30-day periods within the cycle. A sustained decrease overthe study meant there was a sustained decrease within eachpost-randomization treatment cycle.

The analyses of the proportions of patients were the same as thosedescribed for nominal variables.

Analyses to evaluate treatment-by-subgroup interactions were performedfor frequency of headache-free days, days of headache, frequency ofheadaches, days of migraine, frequency of migraines, days of migrainesor probable migraines, frequency of migraines or probable migraines,days of headache (no prophylaxis group), frequency of headaches bybaseline prophylaxis group, days of migraines or probable migraines (noprophylaxis group), frequency of migraines or probable migraines (noprophylaxis group), days with acute analgesic headache medication use(no prophylaxis group), and uses of acute analgesic headache medication(no prophylaxis group). Additional post hoc analyses were performed asdescribed below.

To detect a difference between treatments of 3.0 or more headache-freedays in the mean change from baseline, approximately 45 patients pertreatment were necessary in the placebo non-responder stratum. Thisestimate assumed the usual 2-sided error level of alpha=0.05 and 80%power. It also took into account a standard deviation of 5 units forheadache-free days. The calculation was performed by using nQueryAdvisor (Elashoff, 2000).

Approximately 494 patients were to be screened at 7 to 15 investigativesites to achieve a minimum of 90 patients (45 patients per treatmentgroup) who would receive a third treatment (Day 180) in the placebonon-responder stratum. Of the 494 patients, it was estimated thatapproximately 40% would drop out from Day −60 to Day 0, and 15% woulddrop out between Day 0 and Day 90. The patient drop out rate between Day90 and Day 180 also was expected to be 15%. Using these dropout rates,it was estimated that with 494 patients screened at Day −60, 296patients would remain in the study at Day 0, 252 patients at Day 90, and129 patients at Day 180. Of the patients remaining at Day 180, it wasexpected that 90 would be placebo non-responders, with 45 patients ineach treatment group. The remaining 39 patients at Day 180 were expectedto be placebo-responders.

Of the 571 patients screened and assessed over the Day −60 to Day −30baseline period, 355 were enrolled/randomized at Day 0. At the end ofthe run-in period (Day 0), 279 patients were classified as placebonon-responders and 76 patients as placebo responders. Subsequentlypatients were randomized within each stratum (placebo non-responders andplacebo responders) to receive either BOTOX® or placebo treatment.Within the placebo non-responder stratum, 134 patients received BOTOX®and 145 patients received placebo. Within the placebo responder stratum,39 patients received BOTOX® and 37 patients received placebo. A total of76.9% of patients (273/355) completed the study, including 132 patientswho completed the original protocol requiring only 1 post-randomizationtreatment. Of the patients who discontinued early (22.8% [81/355]): 5.1%(18/355) for lack of efficacy, 1.4% (5/355) for adverse events, 0.3%(1/355) for inability to follow study instructions, 1.1% (4/355) forpersonal reasons, and 2.8% (10/355) were lost to follow up.

All safety and efficacy analyses were performed using the “as-treated”population, consisting of all patients who received treatment at Day 0(Treatment 2). Patients were analyzed according to the treatmentactually received (Day 0), not the treatment they were randomized toreceive. The “as-treated” population included all 355 randomizedpatients.

There were no significant differences between treatment groups indemographic characteristics. Overall, patients were 19 to 65 years ofage (mean, 43.5 years), 84.5% (300/355) were female, and 87.9% (312/355)were Caucasian.

There were no significant differences between treatment groups inbaseline characteristics (Table 3). The mean time from onset of chronicdaily headaches was 14.5 years and the mean age at onset was 28.4 years.The average baseline MIDAS score was 57.6 (indicating severe disability)and Beck Depression Inventory score was 7.8 (indicating no clinicaldepression). The headache diagnosis subtype assigned by the investigatorwas not recorded for approximately half the patients, since this waspart of a protocol amendment initiated midway through the study. Inthose for whom it was recorded, the most frequent subtype wastransformed migraine. Based on telephone data, headache prophylactictreatment was used by 35.8% (127/355) of patients. No patients hadreported predominantly menstrually-associated headaches.

TABLE 3 Baseline Characteristics (As-Treated Population) BOTOX ® 105 Uto Baseline 260 U Placebo Total Characteristic (N = 173) (N = 182) (N =355) P-value Years since 14.8 (12.4) 14.2 (12.5) 14.5 (12.4) 0.655 ^(a)onset, mean (SD) Age at onset, 27.5 (12.3) 29.2 (13.6) 28.4 (13.0) 0.301^(a) mean years (SD) Frequency of 11.2 (6.6)  10.8 (7.9)  11.0 (7.3) 0.274   migraines/probable migraines per 30 day period at baseline Useof  56 (32.4)  71 (39.0)  127 (35.8) 0.192 ^(b) prophylactic treatment,n (%) Experience  0 (0.0)  0 (0.0)  0 (0.0) >0.999 ^(b)  menstrualheadaches, n (%) Baseline MIDAS 55.3 (49.6) 59.8 (59.6) 57.6 (55.0)0.997 ^(a) score, mean (SD) Baseline Beck 7.8 (6.9) 7.9 (6.8) 7.8 (6.9)0.847 ^(a) Depression Inventory score, mean (SD) Mean total dose 190.8 UNA NA NA for the second treatment cycle SD = standard deviation, NA =not applicable, MIDAS = Migraine Disability Assessment. ^(a) P-valuesfor treatment comparisons from the Wilcoxon rank-sum test. ^(b) P-valuesfor treatment comparisons from Pearson's chi-square or Fisher's exacttests.

The most common locations where head pain historically started andended, as reported by patients at baseline, are presented in Table 4

TABLE 4 Location where Headache Pain Historically Starts and EndsReported at Baseline (Number (%) of Patients) BOTOX ® 105 U to 260 UPlacebo Total Location (N = 173) (N = 182) (N = 355) P-value HistoricalLocation Where Pain Starts Frontal/glabellar 125 (72.7) 140 (76.9) 265(74.9) 0.357 Temporalis 100 (58.1) 114 (62.6) 214 (60.5) 0.387Occipitalis  80 (46.5)  85 (46.7) 165 (46.6) 0.971 Historical LocationWhere Pain Ends Frontal/glabellar 123 (71.9) 145 (79.7) 268 (75.9) 0.089Temporalis  98 (57.3) 113 (62.1) 211 (59.8) 0.360 Occipitalis  97 (56.7)111 (61.0) 208 (58.9) 0.416

Other than headache, the most common medical history findings recordedat the baseline visit for all patients were migraine (61.4% [218/355]),gynecologic disorders (58.7% of females [176/300]), musculoskeletaldisorders (44.8% [159/355]), psychiatric disorders (43.9% [156/355]),gastrointestinal disorders (34.1% [121/355]), ear, nose, and throatdisorders (33.5% [119/355]), allergies (31.8% [113/355]), and drugsensitivities (23.7% [84/355]) (Table 14.1-4.1). There were nostatistically significant differences in medical histories between thetreatment groups.

Use of prophylactic headache medication prior to study entry wasreported at the baseline visit for 32.4% (56/173) of the patientstreated with BOTOX® and 39.0% (71/182) treated with placebo (Table14.1-3.4) Acute analgesic medication overuse (≧15 days and ≧2 days/weekper 30-day period) was seen in 52.6% (91/173) of the patients treatedwith BOTOX® and 42.3% (77/182) of the patients treated with placebo(Table 14.2-76.3). There were no statistically significant differencesbetween the treatment groups.

The protocol specified a secondary efficacy variable as the number ofpatients with a 50% or more decrease from baseline in headache days per30-day period with an associated primary time point (Day 180) and group(placebo non-responders). Several other protocol-specified efficacyvariables were examined to determine which patient population was mostresponsive to treatment with BOTOX® and which efficacy variable(s) bestdemonstrated the efficacy of BOTOX® over placebo (summarized for each30-day period).

Secondary Endpoint: Decrease from Baseline of 50% or More Headache DaysPer 30-Day Period

In the placebo non-responder stratum, a significantly higher (p=0.027)percentage of BOTOX® compared with placebo patients had at least a 50%decrease from baseline in the frequency of headache days per 30-dayperiod at Day 180 (32.7% versus 15.0%).

Other Secondary and Exploratory Analyses

In the Analyses of the Frequency of Headaches Per 30-Day Period, astatistically significant change in the frequency of headaches per30-day period was observed at Days 30, 60, 150, 180, 210, and 240 forplacebo non-responders and at Day 180 for placebo responders (Table 5).FIG. 14 presents the mean baseline and the mean changes from baseline inthe frequency of headaches per 30-day period for placebo non-respondersand placebo responders.

TABLE 5 Mean (Standard Deviation) at Baseline and Change from Baselinein the Frequency of Headaches per 30-Day Period for PlaceboNon-responders and Placebo Responders Placebo Non-Responders PlaceboResponders Time BOTOX ® Placebo BOTOX ® Placebo Period (N = 134) (N =145) p-value ^(a) (N = 39) (N = 37) p-value ^(a) Baseline 13.1 (8.4)12.8 (9.0) 0.780 15.0 (5.0) 12.3 (4.9) 0.021 Treatment 1: Placebo(followed by a 30-day run-in period) Treatment 2 Day 30 −3.3 (5.0) −2.0(4.8) 0.028 −6.7 (6.5) −5.2 (4.7) 0.705 Day 60 −4.1 (5.5) −2.6 (5.3)0.018 −7.4 (5.7) −5.8 (4.4) 0.855 Day 90 −3.9 (5.6) −3.2 (5.9) 0.307−8.0 (6.3) −5.7 (4.5) 0.534 Treatment 3 Day 120 −4.6 (5.2) −3.0 (6.3)0.118 −7.6 (5.2) −5.6 (3.3) 0.412 Day 150 −6.3 (6.0) −3.8 (6.2) 0.039−8.5 (5.3) −6.9 (4.6) 0.851 Day 180 −6.1 (5.5) −3.1 (6.8) 0.013 −9.9(4.9) −5.6 (2.8) 0.013 Treatment 4 Day 210 −6.5 (6.9) −3.4 (7.0) 0.021−9.7 (5.8) −6.6 (4.9) 0.259 Day 240 −7.1 (7.3) −4.1 (6.5) 0.035 −9.7(6.1) −8.2 (4.5) 0.948 Day 270 −7.2 (7.4) −4.7 (7.3) 0.172 −9.9 (4.7)−7.4 (5.4) 0.488 Source: Tables 14.2-12.3 and 14.2-12.4. ^(a) Betweentreatment comparison from Wilcoxon rank-sum test.

In the analyses of other protocol-designated efficacy variables, therewere statistically significant differences between BOTOX® and placebo inthe placebo non-responder and placebo responder groups. Additionally,subgroups of patients were identified for which there was a consistentlybetter response to BOTOX® than to placebo.

As a part of the process of identifying patient populations for whichthere was a consistent response to treatment, analyses were performed toidentify significant interaction effects of treatment and variousbaseline patient characteristics. The placebo non-responder and placeboresponder strata were pooled and the resulting data were analyzed tocompare BOTOX® with placebo (pooled population). In the followingsections analyses are presented only for the pooled population.

Frequency of Headaches, Pooled Population

A statistically significant change in the frequency of headaches per30-day period was observed at multiple time points (Days 30, 60, 150,180, 210, and 240) (Table 6). FIG. 15 presents the mean baseline and themean changes from baseline in the frequency of headaches per 30-dayperiod.

The analysis of frequency of headaches demonstrated statisticallysignificant differences between BOTOX® and placebo that favored BOTOX®.

TABLE 6 Mean (Standard Deviation) at Baseline and Change from Baselinein the Frequency of Headaches per 30-Day Period; Pooled PopulationBOTOX ® Placebo Time Period N = 173 N = 182 p-value ^(a) Baseline 13.5(7.7) 12.7 (8.3) 0.339 Treatment 1: Placebo (followed by a 30-day run-inperiod) Post Placebo Run-in −1.9 (4.7) −1.0 (4.0) 0.336 Treatment 2 Day30 −4.1 (5.6) −2.7 (4.9) 0.021 Day 60 −4.8 (5.7) −3.2 (5.3) 0.010 Day 90−4.9 (6.0) −3.7 (5.7) 0.135 Treatment 3 Day 120 −5.4 (5.3) −3.6 (5.8)0.061 Day 150 −6.9 (5.8) −4.6 (6.0) 0.033 Day 180 −7.1 (5.6) −3.7 (6.1)0.001 Treatment 4 Day 210 −7.4 (6.7) −4.2 (6.7) 0.005 Day 240 −7.9 (7.0)−5.1 (6.3) 0.035 Day 270 −8.0 (6.8) −5.4 (7.0) 0.080 ^(a) Betweentreatment comparison from Wilcoxon rank-sum test.

As seen in Table 6 and FIG. 15, the time of the first statisticallysignificant difference between treatment groups in the frequency ofheadaches per 30-day period was at 30 days after the first treatmentfollowing placebo run-in. At this time point, there was a significantdifference (p=0.021) between BOTOX® and placebo demonstrating a rapidonset of effect. The mean changes from baseline were −4.1 for BOTOX® and−2.7 for placebo.

The percentage of patients with at least a 50% decrease from baseline inthe frequency of headaches per 30-day period was significantly greaterfor BOTOX® compared with placebo at Days 180 and 210 (Table 7). In theBOTOX® group, at all time points after Day 120 at least 50% of patientshad at least a 50% decrease from baseline in the frequency of headachesper 30-day period.

TABLE 7 Number (Percentage) of Patients with a Decrease from Baseline of50% or More Headaches per 30-Day Period; Pooled Population Time PeriodBOTOX ® Placebo p-value ^(a) Treatment 1: Placebo (followed by a 30 dayrun-in period) Post Placebo Run-in  23/173 (13.3) ^(b) 20/182 (11.0) 0.506 Treatment 2 Day 30 45/172 (26.2)  47/182 (25.8)  0.942 Day 6060/164 (36.6)  49/166 (29.5)  0.172 Day 90 54/149 (36.2)  49/157 (31.2) 0.352 Treatment 3 Day 120 33/80 (41.3) 28/82 (34.1) 0.351 Day 150 38/75(50.7) 33/80 (41.3) 0.240 Day 180 39/72 (54.2) 30/79 (38.0) 0.046Treatment 4 Day 210 40/70 (57.1) 28/77 (36.4) 0.012 Day 240 39/70 (55.7)32/71 (45.1) 0.206 Day 270 40/69 (58.0) 38/69 (55.1) 0.731 ^(a) Betweentreatment comparison from Person's chi square test or Fisher's exacttest. ^(b) Number of patients with response/number of patients evaluatedat time period (percentage).

The percentage of patients with at least a 30% decrease from baseline inthe frequency of headaches per 30-day period was significantly greaterfor BOTOX® compared with placebo at Days 30 (47.7% versus 37.4%;p=0.050), 60 (53.0% versus 41.0%); p=0.028), 180 (73.6% versus 55.7%;p=0.022), and 210 (72.9% versus 51.9%; p=0.009 Table 14.2-15.3). In theBOTOX® group, at all time points after Day 120 at least 70% of patientshad at least a 30% decrease from baseline in the frequency of headachesper 30-day period.

Table 8 presents the mean baseline and the mean changes from baseline inthe frequency of headaches per 30-day period for patients who completed2 and 3 treatment cycles after the placebo run-in period. The 138patients (69 BOTOX®, 69 placebo) who completed 3 treatment cycles had asustained response to treatment. Over the 270 day treatment period theresponse to treatment with BOTOX® generally continued to improve whilethe response to treatment with placebo remained relatively stable.

TABLE 8 Mean (Standard Deviation) at Baseline and Change from Baselinein the Frequency of Headaches per 30-Day Period for Patients WhoCompleted 2 or 3 Injection Cycles After the Placebo Run-in; PooledPopulation Completed 2 Treatment Cycles After Completed 3 TreatmentCycles After Placebo Run-in Placebo Run-in BOTOX ® Placebo BOTOX ®Placebo Time Period N = 72 N = 79 p-value ^(a) N = 69 N = 69 p-value^(a) Baseline 14.3 (7.5) 12.8 (8.3) 0.183 14.4 (7.5) 12.6 (8.1) 0.136Treatment 1: Placebo (followed by a 30-day run-in period) Treatment 2Day 30 −4.7 (5.3) −3.4 (5.0) 0.072 −4.7 (5.4) −3.4 (5.1) 0.098 Day 60−5.3 (5.3) −3.5 (5.4) 0.037 −5.3 (5.4) −3.7 (5.6) 0.091 Day 90 −4.8(5.6) −3.5 (5.6) 0.198 −4.7 (5.7) −3.4 (5.8) 0.229 Treatment 3 Day 120−5.8 (5.2) −3.6 (5.8) 0.023 −5.7 (5.2) −3.6 (6.0) 0.036 Day 150 −6.8(5.8) −4.5 (5.9) 0.042 −6.8 (5.9) −4.5 (6.1) 0.056 Day 180 −7.1 (5.6)−3.7 (6.1) 0.001 −7.1 (5.6) −3.7 (6.3) 0.001 Treatment 4 Day 210 −7.4(6.8) −4.2 (6.7) 0.008 −7.5 (6.7) −3.9 (6.8) 0.004 Day 240 −7.9 (7.1)−5.1 (6.3) 0.030 −7.9 (7.0) −5.0 (6.3) 0.025 Day 270 −8.0 (6.8) −5.4(7.0) 0.041 −8.0 (6.8) −5.4 (7.0) 0.042 ^(a) Between treatmentcomparison from a Wilcoxon rank-sum test.

Table 9 presents the mean baseline and the mean changes from baseline inthe number of headaches with a duration ≧4 hours and <4 hours per 30-dayperiod. Over the 270-day treatment period, in headaches ≧4 hours induration, the changes from baseline headache count were significantlygreater for BOTOX® than for placebo at every return visit (p≦0.044;Table 14.5-325). A significant difference between the groups was notseen at any return visit for headaches <4 hours in duration.

TABLE 9 Mean Baseline and Change from Baseline in the Frequency ofHeadaches for Headaches of a Durations >4 Hours and <4 Hours per 30-DayPeriod Headaches of a Duration ≧4 Hours Headaches of a Duration <4 HoursTime BOTOX ® Placebo BOTOX ® Placebo Period N = 173 N = 182 p-value ^(a)N = 173 N = 182 p-value ^(a) Baseline 9.6 9.2 0.186 3.9 3.5 0.488Treatment 1: Placebo (followed by a 30-day run-in period) Treatment 2Day 30 −2.9 −1.2 0.001 −1.2 −1.5 0.307 Day 60 −3.4 −1.9 0.017 −1.4 −1.30.784 Day 90 −3.3 −2.0 0.024 −1.6 −1.7 0.848 Treatment 3 Day 120 −3.8−2.0 0.013 −1.6 −1.6 0.867 Day 150 −4.8 −2.8 0.044 −2.0 −1.8 0.906 Day180 −4.6 −2.2 0.005 −2.5 −1.6 0.134 Treatment 4 Day 210 −5.1 −2.4 0.003−2.3 −1.7 0.688 Day 240 −5.1 −3.0 0.016 −2.7 −2.1 0.309 Day 270 −5.5−3.1 0.013 −2.4 −2.2 0.872 ^(a) Between treatment comparison from aWilcoxon rank-sum test.

Post hoc analyses found that for the subpopulation subgroup of patientswho were not using prophylactic headache medications at baseline therewas greater separation and preservation of statistical significance ofBOTOX® versus placebo at most timepoints in the analyses of thefrequency of headaches per 30-day period. Other efficacy variables forwhich there were clinically meaningful differences between BOTOX® andplacebo in this subpopulation subgroup included:

-   -   A 50% reduction from baseline in the frequency of headaches per        30-day period    -   A 30% reduction from baseline in the frequency of headaches per        30-day period    -   Frequency of migraines or probable migraines per 30-day period    -   Number of days and number of uses of acute analgesic headache        medication per 30-day period

The subpopulation subgroup of patients not using prophylactic headachemedications at baseline included 67.6% (117/173) of the patientsrandomized to and treated with BOTOX® and 61.0% (111/182) of thepatients randomized to and treated with placebo. The demographiccharacteristics of BOTOX® and placebo patients using and not usingprophylactic headache medications at baseline are given in Table 10. Forboth of the subgroups of patients, there were no statisticallysignificant differences between the 2 treatment groups with respect totheir baseline characteristics, except for gender in the subgroup ofpatients not using prophylactic medications (p=0.025). Patients notusing prophylactic headache medications at baseline compared with thosewho were using prophylactic headache medications were younger (mean age,42.4 vs. 45.6; p=0.010), had an earlier age of onset of chronic dailyheadache (mean age, 26.9 vs. 31.1 years; p=0.005), had lower BeckDepression Inventory scores (mean score, 7.1 vs. 9.0; p=0.004), and weresimilar with respect to all other baseline variables.

TABLE 10 Baseline Characteristics of Patients Using and Not UsingProphylactic Headache Medications at Baseline; Pooled PopulationProphylactic Headache Medications at Baseline No Yes BOTOX ® PlaceboBOTOX ® Placebo Baseline Characteristic (N = 117) (N = 111) P-Value (N =56) (N = 71) P-Value Age, mean years (SD) 42.2 (10.4) 42.5 (11.5) 0.978^(a) 44.4 (8.5) 46.5 (10.3) 0.232 ^(a) Sex, n (%) Male 11 (9.4) 22(19.8) 0.025 ^(b) 11 (19.6) 11 (15.5) 0.540 ^(b) Female 106 (90.6) 89(80.2) 45 (80.4) 60 (84.5) Race, n (%) Caucasian 102 (87.2) 93 (83.8)0.466 ^(b) 52 (92.9) 65 (91.5) >0.999 ^(b)  Non-Caucasian 15 (12.8) 18(16.2) 4 (7.1) 6 (8.5) Years since onset, 15.3 (13.2) 14.3 (12.8) 0.656^(a) 13.8 (10.7) 14.2 (12.1) 0.864 ^(a) mean (SD) Age at onset, mean26.2 (12.2) 27.6 (13.1) 0.562 ^(a) 30.1 (12.1) 31.8 (13.9) 0.407 ^(a)years (SD) Prophylactic headache medications, n (%) Beta blockers NA NANA 16 (28.6) 21 (29.6) 0.901   Calcium channel NA NA NA 9 (16.1) 18(25.4) 0.204   blockers Anticonvulsants NA NA NA 23 (41.1) 27 (38.0)0.727   Antidepressants NA NA NA 31 (55.4) 43 (60.6) 0.555   BaselineMIDAS score, 54.0 (44.4) 55.7 (60.3) 0.302 ^(a) 58.0 (59.7) 66.1 (58.8)0.264 ^(a) mean (SD) Baseline Beck 6.9 (6.6) 7.3 (7.0) 0.945 ^(a) 9.5(7.4) 8.6 (6.4) 0.739 ^(a) Depression Inventory score, mean (SD) SD =standard deviation, NA = not applicable, NC = not computed. ^(a)P-values for treatment comparisons from the Wilcoxon rank-sum test. ^(b)P-values for treatment comparisons from Pearson's chi-square or Fisher'sexact tests.

Frequency of Headaches in Patients Using and not Using ProphylacticHeadache Medications at Baseline

The mean baseline and mean changes from baseline to each assessment timepoint in the frequency of headache days per 30-day period are presentedin Table 11 and FIG. 16 for the populations of patients using and notusing prophylactic headache medications at baseline. The types ofprophylactic headache medications used at baseline included betablockers, calcium channel blockers, anticonvulsants, and antidepressants(excluding serotonin uptake inhibitors [eg, PROZAC®] since there is noevidence of any effect in headache for this class).

For patients who were using prophylactic headache medications atbaseline, the mean changes from baseline in the frequency of headachesper 30-day period were greater for BOTOX® compared with placebo at Day120 through Day 270 by 1.0 to 2.7. The differences in the changes frombaseline were statistically significantly different only at Day 180. Forpatients who were not using prophylactic headache medications atbaseline, the mean changes from baseline were greater for BOTOX®compared with placebo by 2.2 to 4.2. The differences between treatmentgroups were either statistically significant (p≦0.032) or marginallystatistically significant (p≦0.072) at all time points.

TABLE 11 Mean (Standard Deviation) at Baseline and Change from Baselinein the Frequency of Headaches per 30-Day Period by Use of ProphylacticHeadache Medications at Baseline; Pooled Population Use of ProphylacticHeadache Medications at Baseline Yes No Time BOTOX ® Placebo BOTOX ®Placebo Period N = 56 N = 71 p-value ^(a) N = 117 N = 111 p-value ^(a)Baseline 12.4 (7.5) 12.5 (8.6) 0.855 14.1 (7.9) 12.9 (8.2) 0.205Treatment 1: Placebo (followed by a 30-day run-in period) Treatment 2Day 30 −2.8 (4.1) −2.8 (3.7) 0.887 −4.7 (6.1) −2.5 (5.6) 0.004 Day 60−3.5 (4.4) −3.5 (4.6) 0.836 −5.5 (6.1) −3.0 (5.7) 0.005 Day 90 −3.6(5.0) −4.8 (4.9) 0.201 −5.6 (6.3) −3.0 (6.1) 0.011 Treatment 3 Day 120−5.3 (4.3) −4.0 (4.9) 0.255 −5.5 (6.0) −3.3 (6.5) 0.072 Day 150 −5.7(5.1) −4.7 (5.3) 0.564 −7.8 (6.2) −4.5 (6.6) 0.032 Day 180 −6.6 (5.0)−3.9 (4.7) 0.030 −7.5 (6.0) −3.6 (7.3) 0.007 Treatment 4 Day 210 −6.7(5.5) −4.7 (5.1) 0.138 −7.9 (7.4) −3.7 (7.9) 0.023 Day 240 −6.6 (6.0)−5.0 (5.5) 0.279 −8.7 (7.6) −5.1 (7.1) 0.062 Day 270 −6.9 (6.3) −5.2(5.5) 0.369 −8.8 (7.1) −5.6 (8.1) 0.062 ^(a) Between treatmentcomparison from a Wilcoxon rank-sum test.

Compared with patients who used prophylactic headache medications atbaseline, patients who did not use prophylactic headache medications atbaseline had mean changes from baseline that generally were greater forBOTOX®-treated patients and smaller for placebo-treated patients.

Analyses by Type of Prophylactic Headache Medication Used at Baseline

Analyses of the frequency of headaches per 30-day period were performedfor the baseline use of beta-blockers, calcium channel blockers,anticonvulsants, and antidepressants.

There were no statistically significant differences between treatmentgroups at any time point in the mean change from baseline in thefrequency of headaches per 30-day period for patients usingbeta-blockers at baseline or calcium channel blockers at baseline. Atbaseline, 37 patients (16 BOTOX®, 21 placebo) were using beta-blockersand 27 patients (9 BOTOX®, 18 placebo) were using calcium channelblockers. The analyses of patients not using beta blockers at baselineand analyses of patients not using calcium channel blockers at baselineshowed statistically significant differences between treatment groups atmultiple time points that were comparable to those for the larger groupof patients not using prophylactic headache medications at baseline(Table 11).

For patients using anticonvulsants at baseline (23 BOTOX®, 27 placebo)there were no statistically significant differences between treatmentgroups at any time point, except at Day 180 (p=0.006), in the changefrom baseline in the frequency of headaches per 30-day period. From Day120 through Day 270, the mean decrease from baseline was greater forBOTOX® by 2.2 to 4.9 headaches per 30-day period. For patients not usinganticonvulsants at baseline, the changes from baseline weresignificantly greater (p≦0.026) for BOTOX® at Days 30, 60, 180, and 210.At these time points the mean changes were greater for BOTOX® by 1.6 to3.2 headaches per 30-day period.

For patients using antidepressants at baseline (31 BOTOX®, 43 placebo)there were no statistically significant differences between treatmentgroups at any time point, except at Day 210 (p=0.048), in the changefrom baseline in the frequency of headaches per 30-day period. From Day120 through Day 270, the mean decrease from baseline was greater forBOTOX® by 1.6 to 3.7 headaches per 30-day period. For patients not usingantidepressants at baseline, from Day 60 through Day 270, the meandecrease from baseline was greater for BOTOX® by 1.7 to 3.6 headachesper 30-day period. The changes from baseline were significantly greater(p≦0.020) for BOTOX® at Days 30, 60, and 180.

Decrease from Baseline of 50% or More Headaches Per 30-Day Period inPatients with and without Concomitant Headache Prophylaxis Using and notUsing Prophylactic Headache Medications at Baseline

The percentages of patients at each assessment time point with at leasta 50% decrease from baseline in the frequency of headaches per 30-dayperiod (defined as a responder) are presented in Table 12 for patientsusing and not using prophylactic headache medications at baseline.

For patients using prophylactic headache medications at baseline, therewere no statistically significant differences between BOTOX® andplacebo. For patients not using prophylactic headache medications atbaseline, from Day 150 through Day 270 at least 50% of BOTOX®-treatedpatients were responders. The differences between BOTOX® and placebowere statistically significant at Days 150 and 210. At these timepoints, the response rate for BOTOX® was greater than the response ratefor placebo by at least 20%.

TABLE 12 Number (Percentage) of Patients with a Decrease from Baselineof 50% or More Headaches per 30-Day Period by Use of ProphylacticHeadache Medications at Baseline; Pooled Population Using ProphylacticHeadache Medications at Baseline Yes No Time BOTOX ® Placebo BOTOX ®Placebo Period N = 56 N = 71 p-value ^(a) N = 117 N = 111 p-value ^(a)Treatment 1: Placebo (followed by a 30-day run-in period) Post Placebo4/56 (7.1%) ^(b) 7/71 (9.9%) 0.754 19/117 (16.2%) 13/111 (11.7%) 0.325Run-in Treatment 2 Day 30 10.56 (17.9%) 17/71 (23.9%) 0.405 35/116(30.2%) 30/111 (27.0%) 0.600 Day 60 15/54 (27.8%) 20/66 (30.3%) 0.76245/110 (40.9%) 29/100 (29.0%) 0.071 Day 90 15/53 (28.3%) 22/63 (34.9%)0.446 39/96 (40.6%) 27/94 (28.7%) 0.085 Treatment 3 Day 120 17/34(50.0%) 17/39 (43.6%) 0.584 16/46 (34.8%) 11/43 (25.6%) 0.345 Day 15013/30 (43.3%) 19/38 (50.0%) 0.584 25/45 (55.6%) 14/42 (33.3%) 0.037 Day180 16/28 (57.1%) 15/38 (39.5%) 0.155 23/44 (52.3%) 15/41 (36.6%) 0.146Treatment 4 Day 210 18/29 (62.1%) 17/38 (44.7%) 0.159 22/41 (53.7%)11/39 (28.2%) 0.021 Day 240 18/29 (62.1%) 17/35 (48.6%) 0.280 21/41(51.2%) 15/36 (41.7%) 0.402 Day 270 16/29 (55.2%) 19/33 (57.6%) 0.84924/40 (60.0%) 19/36 (52.8%) 0.526 ^(a) Between treatment comparison fromPerson's chi-square test or Fisher's exact test. ^(b) Number of patientswith response/number of patients evaluated at time period (percentage).

Decrease from Baseline of 30% or More Headaches Per 30-Day Period inPatients Using and not Using Prophylactic Headache Medications atBaseline

The percentages of patients at each assessment time point with at leasta 30% decrease from baseline in the frequency of headaches per 30-dayperiod are presented in Table 13 for patients using and not usingprophylactic headache medications at baseline.

For patients using prophylactic headache medications at baseline, therewere no statistically significant differences between BOTOX® andplacebo. For patients not using prophylactic headache medications atbaseline, from Day 30 through Day 270 at least 50% of BOTOX®-treatedpatients had at least a 30% decrease in the frequency of headaches per30-day period. The differences between BOTOX® and placebo werestatistically significant at Days 30, 60, 150, 180, and 210. At thesetime points, the response rates for BOTOX® was greater than the responserates for placebo by 16.4 to 26.2%.

TABLE 13 Number (Percentage) of Patients with a Decrease from Baselineof 30% or More Headaches per 30-Day Period by Use of ProphylacticHeadache Medications at Baseline; Pooled Population Use of ProphylacticHeadache Medications at Baseline Time Yes No Period BOTOX ® Placebop-value ^(a) BOTOX ® Placebo p-value ^(a) Treatment 1: Placebo (followedby a 30-day run-in period) Post Placebo 15/56 (26.8%) 18/71 (25.4%)0.855 24/117 (20.5%) 29/111 (26.1%) 0.316 Run-in Treatment 2 Day 3021/56 (37.5%) 28/71 (39.4%) 0.824 61/116 (52.6%) 40/111 (36.0%) 0.012Day 60 25/54 (46.3%) 28/66 (42.4%) 0.671 62/110 (56.4%) 40/100 (40.0%)0.018 Day 90 21/53 (39.6%) 36/63 (57.1%) 0.060 59/96 (61.5%) 47/94(50.0%) 0.112 Treatment 3 Day 120 20/34 (58.8%) 23/39 (59.0%) 0.99026/46 (56.5%) 20/43 (46.5%) 0.345 Day 150 18/30 (60.0%) 26/38 (68.4%)0.471 35/45 (77.8%) 24/42 (57.1%) 0.040 Day 180 20/28 (71.4%) 24/38(63.2%) 0.481 33/44 (75.0%) 20/41 (48.8%) 0.013 Treatment 4 Day 21023/29 (79.3%) 22/38 (57.9%) 0.064 28/41 (68.3%) 18/39 (46.2%) 0.045 Day240 22/29 (75.9%) 23/35 (65.7%) 0.376 31/41 (75.6%) 22/36 (61.1%) 0.171Day 270 20/29 (69.0%) 23/33 (69.7%) 0.950 30/40 (75.0%) 23/36 (63.9%)0.292 ^(a) Between treatment comparison from Person's chi-square test.

Frequency of Headaches by Disease Onset (10 to 20, >20 Years)

Analyses of the frequency of headaches per 30-day period for patientswho were 10 to 20 years and >20 years since disease onset are given inTable 14. The response to BOTOX® was consistently better than theresponse to placebo over the entire treatment period for patients withdisease onset of 10 to 20 years with a statistically significantdifference only at Day 180 and for patients with disease onset of >20years with statistically significant differences at Days 30, 60, and210. Of note is the observation that for the >20 years subgroup ofpatients the response to placebo treatment was consistently andconsiderably lower compared with the response to treatment for the 10 to20 years subgroup of patients.

TABLE 14 Mean (Standard Deviation) Baseline and Change from Baseline inthe Frequency of Headaches per 30-Day Period by Time From Disease Onset(10 to 20 and >20 Years); Pooled Population Disease Onset 10 to 20 YearsDisease Onset >20 Years Time BOTOX ® Placebo BOTOX ® Placebo Period N =53 N = 53 p-value ^(a) N = 46 N = 48 p-value ^(a) Baseline 13.2 (7.1)11.5 (8.1) 0.170 14.1 (7.9) 14.2 (9.5) 0.931 Treatment 1: Placebo(followed by a 30-day run-in period) Treatment 2 Day 30 −3.6 (5.0) −3.4(5.1) 0.472 −4.7 (5.0) −1.9 (4.2) 0.014 Day 60 −4.9 (5.0) −4.1 (4.9)0.269 −5.8 (5.8) −1.8 (5.2) 0.003 Day 90 −4.9 (5.6) −4.4 (4.9) 0.693−5.4 (5.4) −2.8 (6.2) 0.078 Treatment 3 Day 120 −6.2 (5.8) −4.5 (5.3)0.205 −6.1 (4.7) −2.5 (6.3) 0.107 Day 150 −7.7 (6.2) −5.7 (5.1) 0.244−6.3 (5.1) −3.5 (6.6) 0.146 Day 180 −8.1 (6.4) −4.8 (5.2) 0.045 −6.1(4.6) −2.3 (6.3) 0.055 Treatment 4 Day 210 −8.3 (6.8) −6.4 (5.7) 0.256−6.7 (6.9) −1.4 (6.9) 0.025 Day 240 −8.2 (6.7) −6.1 (5.6) 0.278 −8.1(7.8) −3.4 (6.7) 0.074 Day 270 −7.4 (6.2) −6.3 (6.1) 0.481 −8.8 (8.5)−4.8 (6.9) 0.209 ^(a) Between treatment comparison from a Wilcoxonrank-sum test.

Frequency of Headaches by Baseline Headache Day Frequency (20 to 24 and25 to 30 Headache-Days Per 30-Day Period)

Analyses of the frequency of headaches per 30-day period by headache-dayfrequency at baseline (20 to 24 and 25 to 30 headache-days) aresummarized in Table 15. The response to BOTOX® was consistently betterthan the response to placebo over the entire treatment period forpatients with a baseline headache-day frequency of 20 to 24 withstatistically significant differences at Days 60 and 180, and forpatients with a baseline headache-day frequency of 25 to 30 withstatistically significant differences at Days 30, 60, and 180. At eachtime point, the difference between the mean changes for BOTOX® andplacebo were greater for patients with a baseline headache-day frequencyof 25 to 30.

TABLE 15 Mean (Standard Deviation) at Baseline and Change from Baselinein the Frequency of Headaches per 30-Day Period for Patients withHeadache-Day Frequency of 20 to 24 and 25 to 30 per 30-Day Period atBaseline; Pooled Population Headache-Day Frequency of 20 to 24 PerHeadache-Day Frequency of 25 to 30 30-Day Period Per 30-Day Period TimeBOTOX ® Placebo BOTOX ® Placebo Period N = 53 N = 54 p-value ^(a) N = 70N = 81 p-value ^(a) Baseline 16.6 (5.9) 14.8 (6.3) 0.127 11.5 (10.0)11.5 (10.7) 0.769 Treatment 1: Placebo (followed by a 30-day run-inperiod) Treatment 2 Day 30 −5.7 (5.1) −4.2 (5.4) 0.248 −3.5 (6.4) −1.2(4.5) 0.014 Day 60 −6.9 (5.7) −4.7 (5.6) 0.036 −3.9 (6.2) −1.4 (4.9)0.015 Day 90 −6.5 (6.1) −4.6 (5.7) 0.158 −4.0 (6.4) −2.9 (5.9) 0.318Treatment 3 Day 120 −6.9 (5.9) −4.6 (6.1) 0.166 −4.1 (5.7) −2.5 (5.9)0.154 Day 150 −9.0 (6.0) −6.4 (5.7) 0.137 −6.2 (6.5) −2.7 (5.6) 0.059Day 180 −8.9 (6.0) −5.0 (6.0) 0.038 −6.0 (6.0) −2.5 (5.8) 0.019Treatment 4 Day 210 −9.6 (7.4) −6.3 (6.1) 0.064 −6.5 (7.6) −2.4 (6.1)0.104 Day 240 −10.1 (7.2) −6.8 (5.5) 0.125 −7.5 (8.6) −3.1 (6.5) 0.057Day 270 −10.0 (6.1) −7.3 (6.1) 0.080 −7.6 (9.1) −3.3 (7.7) 0.139 ^(a)Between treatment comparison from a Wilcoxon rank-sum test.

Frequency of Headaches by Baseline Analgesic Acute Headache MedicationOveruse

Medication overuse was defined as use of any acute analgesic medicationfor ≧15 days and ≧2 days/week. Based on this definition, for patientswho did not have overuse of acute analgesic medications at baselinethere were no statistically significant differences between BOTOX® andplacebo in the changes from baseline in the frequency of headaches per30-day period at any time point (Table 16). For patients with overuse ofacute analgesic medications at baseline, except for Day 90, thedifference in the decrease from baseline were significantly greater forBOTOX® than placebo. The mean decreases from baseline were greater forBOTOX® by 2.0 to 5.6 headaches at all time points, except at Day 90(Table 16).

TABLE 16 Mean (Standard Deviation) at Baseline and Change from Baselinein the Frequency of Headaches per 30-Day Period for Patients with AcuteAnalgesic Headache Medication Overuse (No, Yes) at Baseline; PooledPopulation Any Analgesic Overuse for ≧15 Days Any Analgesic Overuse for≧15 Days and ≧2 Days/Week, No and ≧2 Days/Week, Yes Time BOTOX ® PlaceboBOTOX ® Placebo Period N = 82 N = 105 p-value ^(a) N = 91 N = 77 p-value^(a) Baseline 11.7 (6.7) 11.1 (7.5) 0.477 15.2 (8.2) 14.9 (8.9) 0.592Treatment 1: Placebo (followed by a 30-day run-in period) Treatment 2Day 30 −3.5 (4.8) −2.8 (5.0) 0.320 −4.5 (6.1) −2.5 (4.9) 0.020 Day 60−4.0 (5.3) −3.7 (5.4) 0.756 −5.6 (5.9) −2.6 (5.2) 0.001 Day 90 −4.5(5.5) −3.7 (5.8) 0.726 −5.2 (6.4) −3.7 (5.6) 0.168 Treatment 3 Day 120−4.6 (3.9) −3.6 (6.3) 0.342 −6.2 (6.4) −3.6 (5.2) 0.044 Day 150 −5.6(4.7) −4.9 (5.7) 0.585 −8.2 (6.6) −4.3 (6.3) 0.018 Day 180 −6.1 (4.7)−3.8 (6.0) 0.088 −8.1 (6.3) −3.6 (6.4) 0.003 Treatment 4 Day 210 −5.5(5.6) −4.4 (7.1) 0.495 −9.3 (7.3) −3.9 (6.2) 0.003 Day 240 −5.7 (4.9)−5.5 (6.6) 0.885 −10.1 (8.1)  −4.5 (6.1) 0.007 Day 270 −6.3 (4.9) −5.8(7.5) 0.800 −9.5 (8.0) −4.9 (6.4) 0.017 ^(a) Between treatmentcomparison from a Wilcoxon rank-sum test.

Frequency of Headaches by Baseline MIDAS Score of Moderate and Severe

Few patients had baseline MIDAS scores of minimal (8 BOTOX®, 10 placebo)or mild (9 BOTOX®, 16 placebo). For patients with a baseline MIDAS scoreof moderate (21 BOTOX®, 25 placebo), at all time points there were nostatistically significant differences between BOTOX® and placebo.However, after Day 60, the mean decreases from baseline were greater forBOTOX® by 2.1 to 5.8 headaches per 30-day period. For patients with abaseline MIDAS score of severe (134 BOTOX®, 131 placebo), the decreasesin the frequency of headaches per 30-day period were significantlygreater (p≦0.046) for BOTOX® at Days 30, 60, 180, 210, and 240. At thesetime points, the mean decreases were greater for BOTOX® by 1.3 to 3.2headaches per 30-day period.

Type of Headaches

Each headache was classified as migraine (ICHD 1.) or non-migraine (ICHD2; eg, tension-type headache). All patients experienced at least 1migraine during the baseline period, suggesting that all patients mayactually have a diagnosis of migraine even though this diagnosis was notrecognized by the investigator for all patients. It is not unusual formigraine patients to be under diagnosed (Lipton and Stewart, 1998).During the study, patients experienced both migraine and non-migraineheadaches. The majority of headaches in both treatment groups wereclassified as migraine (per the ICHD criteria).

Migraine

The mean baseline and mean changes from baseline in the frequency ofmigraine (ICHD 1.1 or 1.2) or probable migraine (ICHD 1.5.1) headachesper 30-day period are shown in Table 17. At all time points thedecreases from baseline were greater for BOTOX® compared with placeboand were significantly greater OD 0.048) at Days 120, 180, and 210. Atthese time points the mean decreases from baseline were greater forBOTOX® by 1.6 to 2.8 headaches.

TABLE 17 Mean (Standard Deviation) at Baseline and Change from Baselinein the Frequency of Migraine and Probable Migraine Headaches per 30-DayPeriod; Pooled Population Time BOTOX ® Placebo Period N = 173 N = 182p-value ^(a) Baseline 11.2 (6.6) 10.8 (7.9) 0.274 Treatment 1: Placebo(followed by a 30-day run-in period) Treatment 2 Day 30 −3.2 (4.9) −2.7(4.4) 0.335 Day 60 −3.9 (5.2) −3.1 (5.0) 0.134 Day 90 −3.9 (5.6) −3.5(5.3) 0.768 Treatment 3 Day 120 −4.7 (5.0) −3.1 (5.5) 0.048 Day 150 −5.7(5.2) −3.7 (6.0) 0.057 Day 180 −5.8 (5.4) −3.0 (5.7) 0.002 Treatment 4Day 210 −5.9 (5.9) −3.3 (6.3) 0.018 Day 240 −6.0 (5.6) −4.2 (5.7) 0.083Day 270 −6.4 (5.8) −4.3 (6.5) 0.067 ^(a) Between treatment comparisonfrom a Wilcoxon rank-sum test.

Non-Migraine Headaches

The mean frequency of non-migraine headaches per 30-day period atbaseline was 2.3 and 1.8 in the BOTOX® and placebo groups, respectively.There were no statistically significantly differences (p 0.065) betweenBOTOX® and placebo in the changes from baseline in the frequency ofnon-migraine headaches per 30-day period at all time points except atDay 90 (p=0.034). At all time points after the run-in period, the meandecreases from baseline were greater for BOTOX® by 0.3 to 1.0non-migraine headaches. At Day 90 the mean decrease was 1.0 for BOTOX®and 0.2 for placebo.

Acute Headache Medication Use

Acute Analgesic Headache Medication Use and Overuse There were fewstatistically significant differences between treatment groups in theuse of any acute headache medication (eg, triptans, opioids, etc) duringany 30-day treatment period. There were also no statisticallysignificant between-group differences for the individual categories ofmedication, i.e., ergotamines, triptans, simple analgesics, oranti-emetics. There were significant differences between treatmentgroups for opioids at Day 210 (11.4% [8/70], BOTOX®, 24.7% [19/77]placebo; p=0.038 and for combination therapies at Day 210 (34.3% [24/70]BOTOX®, 18.2% [14/77] placebo; p=0.026) and Day 240 (32.9% [23/70]BOTOX®, 18.3% [13/71] placebo; p=0.048.

Acute medication overuse was defined as ≧15 days/month and ≧2/week forany medication use, simple analgesics, and antiemetics, and ≧10 days permonth and ≧2/week for triptans, ergotamines, opioids and combinationacute medications. For acute medication overuse, there were nostatistically significant between group differences for any acuteanalgesic, ergotamines, triptans, opioids, combinations, oranti-emetics. Statistically significant between-group differences wereobserved in the category of simple analgesics at Day 90 (10.1% [15/149]of BOTOX® patients and 3.8% [6/157] of placebo patients [p=0.031]).

Acute Analgesic Headache Medication Use (Number of Days and Number ofUses)

There were no statistically significant differences between the BOTOX®and placebo groups in the number of days with any acute analgesicheadache medication use or in the number of uses of any acute analgesicheadache medication use at any time point. At all time points, thenumber of days with any acute analgesic headache medication use and thenumber of uses of any acute analgesic headache medications was decreasedin both treatment groups with greater decreases in the BOTOX® group.

The baseline characteristics of patients overusing and not overusingacute analgesic headache medication at baseline at summarized in Table18. Patients overusing acute analgesic headache medications weresignificantly older at baseline (mean age, 45.6 versus 41.6 years;p=0.001), otherwise there were no statistically significant differencesbetween the demographic characteristics of overusers and non-overusersof acute analgesic headache medications at baseline.

TABLE 18 Baseline Characteristics of Patients With and Without AnalgesicHeadache Medication Overuse at Baseline; Pooled Population AnalgesicHeadache Medication Overuse ^(a) at Baseline Yes No BaselineCharacteristic N = 168 187 P-Value Age, mean years (SD) 45.6 (9.6)  41.6 (11.0)  0.001 ^(b) Sex, n (%) Male 32 (19.0) 23 (12.3) 0.079 ^(c)Female 136 (81.0)  164 (87.7)  Race, n (%) Caucasian 151 (89.9)  161(86.1)  0.275 ^(c) Non-Caucasian 17 (10.1) 26 (13.9) Years since onset,15.7 (12.6)  13.5 (12.2)  0.075 ^(b) mean (SD) Age at onset, mean 29.3(12.4)  27.5 (13.4)  0.153 ^(b) years (SD) Prophylactic headache 61(36.3) 66 (35.3) 0.842 ^(c) medications, n (%) Beta blockers 16 (9.5) 21 (11.2) 0.599 ^(c) Calcium channel 14 (8.3)  13 (7.0)  0.624 ^(c)blockers Anticonvulsants 23 (13.7) 27 (14.4) 0.840 ^(c) Antidepressants38 (22.6) 36 (19.3) 0.435 ^(c) Baseline MIDAS score, 54.3 (54.7)  60.6(55.2)  0.144 ^(b) mean (SD) Baseline Beck 7.9 (6.6)  7.8 (7.1)  0.577^(b) Depression Inventory score, mean (SD) SD = standard deviation. ^(a)Overuse = use for ≧15 days and ≧2 days/week ^(b) P-values for treatmentcomparisons from the Wilcoxon rank-sum test. ^(c) P-values for treatmentcomparisons from Pearson's chi-square or Fisher's exact tests.

There were no statistically significant differences between the 2treatment groups in the change from baseline in the number of uses or inthe number of days of use of acute analgesic headache medications at alltime points. In both treatment groups, the number of uses and days ofuse were decreased from baseline and, at all time points there was agreater decrease for BOTOX®-treated than for placebo-treated patients.

Use of any Acute Analgesic Headache Medications in Patients withoutHeadache Prophylaxis Use at Baseline

The number of uses of any acute analgesic headache medications and thenumber of days these medications were used for patients who were notusing prophylactic headache medications at baseline and for each 30-daytreatment period are summarized in Table 19 and in FIG. 16,respectively.

At all postbaseline time points, in the BOTOX® compared with the placebogroup there was a greater decrease in the number of uses of acuteanalgesic headache medications, with a statistically significantdifference at Days 90 and 210 (p≦0.047). This also was observed in theanalysis of the mean number of days acute analgesic headache medicationswere used, with statistically significant differences at Days 90, 180,210, and 240 (p≦0.033).

TABLE 19 Mean (Standard Deviation) at Baseline and Change from Baselinein the Number of Uses and Days of Use of Acute Analgesic HeadacheMedications per 30-Day Period for Patients Not Using ProphylacticHeadache Medications at Baseline; Pooled Population Number of Uses ofAnalgesic Acute Days with Analgesic Acute Headache Headache MedicationsMedication Use Time BOTOX ® Placebo BOTOX ® Placebo Period N = 117 N =111 p-value ^(a) N = 117 N = 111 p-value ^(a) Baseline  25.1 (17.7) 21.0(15.9) 0.058 15.5 (8.4) 13.5 (8.3) 0.069 Treatment 1: Placebo (followedby a 30-day run-in period) Treatment 2 Day 30  −8.7 (13.3) −5.7 (10.2)0.096 −4.5 (6.3) −3.3 (5.9) 0.206 Day 60 −10.3 (14.8) −6.4 (10.1) 0.076−5.5 (7.0) −3.6 (6.6) 0.052 Day 90 −10.3 (14.2) −6.2 (9.9)  0.047 −5.7(6.7) −3.3 (6.8) 0.025 Treatment 3 Day 120 −10.0 (16.7) −7.7(9.0)  >0.999 −5.7 (6.9) −4.1 (5.9) 0.427 Day 150 −13.2 (16.5) −8.7(10.6) 0.199 −7.9 (6.8) −5.2 (6.7) 0.098 Day 180 −12.9 (15.5) −7.9(11.4) 0.110 −7.8 (6.3) −4.1 (6.6) 0.015 Treatment 4 Day 210 −14.6(17.3) −7.4 (11.3) 0.018 −8.5 (7.6) −4.0 (7.4) 0.011 Day 240 −15.8(18.1) −8.5 (9.5)  0.151 −9.3 (8.1) −4.7 (7.0) 0.033 Day 270 −15.6(15.9) −9.2 (11.3) 0.093 −8.8 (7.6) −5.2 (7.3) 0.086 ^(a) Betweentreatment comparison from a Wilcoxon rank-sum test.

The study compared BOTOX® and placebo; there was no active control. Arange of BOTOX® doses to be used was specified (105 to 260 U),therefore, the exact dose used was not fixed. Depending on the locationand severity of the patients' headache pain, the number of injectionsites and the dosage to be administered for the specified frontal andposterior muscle areas, could be customized for each patient (within aspecified range). Therefore, a dose-response effect could not beevaluated. The same dose and injection administered for treatment 1 wasto be replicated at each subsequent treatment.

Overall, 97.7% (347/355) of patients received acute headache medicationswhile in the study, with similar proportions in each treatment group:98.3% (170/173) of patients in the BOTOX® group and 97.3% (177/182) inthe placebo group.

The most common classes of concomitant acute headache medications (>10%)taken during the study were selective 5HT1-receptor agonists (67.0%,238/355), anilides (62.3%, 221/355), propionic acid derivatives (55.2%,196/355), all other therapeutic products (39.4%, 140/355), natural opiumalkaloids (22.3%, 79/355), unknown class (15.8%, 56/355), salicylic acidand derivatives (14.6%, 52/355), and hypnotics and sedatives (13.5%,48/355). There were no notable differences in the types or frequenciesof acute headache medication use between the BOTOX® and placebo groups.

Overall, 87.6% (311/355) of patients received concomitant medications(other than acute headache medications), with similar proportions ineach treatment group: 90.2% (156/173) of patients in the BOTOX® groupand 85.2% (155/182) in the placebo group.

The most common classes of concomitant medications (>10%) taken duringthe study were selective serotonin reuptake inhibitors (21.4%, 76/355),non-selective monoamine reuptake inhibitors (16.9%, 60/355), natural andsemisynthetic estrogens (15.2%, 54/355), thyroid hormones (11.5%,41/355), benzodiazepine derivatives (11.3%, 40/355), and progestogensand estrogens/fixed combinations (11.0%, 39/355). There were no notabledifferences in the types or frequencies of concomitant medication usebetween the BOTOX® and placebo groups.

A total of 35.8% (127/355) of patients were taking a headacheprophylaxis medication during baseline. These included 10.4% (37/355) onbeta blockers, 7.6% (27/355 on calcium channel blockers, 14.1% (50/355)on anti-convulsants, and 20.8% (74/355) on anti-depressants. There wereno statistically significant differences between the BOTOX® and placebogroups in the number of patients using any of the aforementionedheadache prophylactic medications.

Efficacy Conclusions

In this phase 2 study the secondary endpoint of the proportion ofpatients with a decrease from baseline of 50% or more headache days per30-day period in the non-responder strata was met. There were occasionalstatistically significant differences in the analyses of otherprotocol-designated variables (eg, frequency of headaches, incidence ofsubjects with a decrease from baseline of 50% or more headaches per30-day period, frequency of migraines per 30-day period) when analyseswere performed on both placebo non-responders and placebo respondersubpopulations. No treatment-by responder interaction was statisticallysignificant; therefore, stratification by respond/nonresponder was notnecessary.

Further post hoc analyses were performed that identified the followingpatient populations that were most responsive to treatment with BOTOX®relative to placebo:

-   -   The pooled placebo non-responder and placebo responder stratum        (pooled population).    -   Patients not using prophylactic headache medication at baseline        compared with patients using prophylactic headache medications        at baseline.    -   Patients with more frequent days of headache at baseline (i.e.,        20 to 24 and 25 to 30 headache days) compared with those with        less frequent days of headache at baseline (i.e., <20 headache        days).    -   Patients with more years of chronic headache disease (i.e., >20        years) compared with those with less chronicity (i.e., <10 years        and 10 to 20 years).    -   Patients with acute analgesic medication overuse at baseline        compared with those without acute analgesic medication overuse.        From the post hoc analyses of the pooled population of patients,        it is concluded that:    -   There was a persistent statistically significant decrease in the        frequency of headaches for patients treated with BOTOX® compared        with placebo at multiple timepoints. There was an accompanying        decrease in the use of and days of use of any acute analgesic        headache medications for patients treated with BOTOX® compared        with those treated with placebo.    -   The efficacy endpoint that best demonstrated BOTOX® efficacy        over placebo was the frequency of headaches per 30-day period.

During the placebo run-in period (first treatment cycle 1, Day −30 toDay 0) all patients received placebo on Day −30. On Day 0, patients wererandomized to receive 3 treatment cycles of intramuscular injections ofBOTOX® or placebo. Of the 355 patients enrolled in the study, 173received 105 U to 260 U BOTOX® and 182 received placebo. The maximumdose of BOTOX® that patients could have received according to theprotocol was 260 U per treatment cycle for each of 3 treatment cyclesfor a total cumulative exposure of 780 U.

Dose

The mean (median) total dose of BOTOX® for the second, third, and fourthtreatment cycles was 190.8 U (200 U), 190.9 U (200 U), and 190.5 (200U), respectively. The mean and median doses of BOTOX® injected into eachmuscle group for the second, third, and fourth treatment cycles arepresented in Table 20. Of note is the observation that the optionalinjection of the masseter was administered to less than half of thepatients in both the BOTOX® and placebo groups.

TABLE 20 Mean (Median) Dose of BOTOX ® Injected into Each Muscle Groupper Treatment Muscle Injected Treatment Treatment Treatment (AllowableDose Cycle 2 Cycle 3 Cycle 4 Range) (Day 0) (Day 90) (Day 180)Frontal/glabellar (25 to 38.0 U (40 U) 37.3 U (40 U) 37.1 U (40 U) 40 U)Occipitalis (20 U) 19.8 U (20 U) 19.8 U (20 U) 19.7 U (20 U) Temporalis(20 to 42.0 U (40 U) 42.7 U (45 U) 43.7 U (45 U) 50 U) Masseter(optional; 0 8.0 U (0 U) 7.6 U (0 U) 6.5 U (0 U) to 50 U) Trapezius (20to 60 U) 47.4 U (60 U) 48.3 U (60 U) 48.4 U (60 U) Semispinalis (10 to18.2 U (20 U) 18.0 U (20 U) 17.9 U (20 U) 20 U) Splenius capitis (10 to18.6 U (20 U) 18.1 U (20 U) 18.1 U (20 U) 20 U) Note: During treatmentcycle 1 all patients were treated with placebo.

Number of Sites Injected

The mean (median) total number of sites injected with BOTOX® for thefirst, second, and third treatments was 32.0 (30), 31.6 (29) and 31.8(29), respectively. The mean (median) number of sites injected withBOTOX® per muscle group for the first, second, and third injections arepresented in Table 21.

TABLE 21 Mean (Median) Number of Sites BOTOX ® Injected per Muscle Groupper Treatment Cycle Muscle Injected Treatment Treatment Treatment(Allowable Dose Cycle 2 Cycle 3 Cycle 4 Range) (Day 0) (Day 90) (Day180) Frontal/glabellar (25 to 9.5 (9.0)  9.8 (10.0)  9.7 (10.0) 40 U)Occipitalis (20 U) 3.0 (2.0) 2.8 (2.0) 2.9 (2.0) Temporalis (20 to 6.5(6.0) 6.3 (6.0) 6.4 (6.0) 50 U) Masseter (optional; 0 1.3 (0.0) 1.2(0.0) 1.2 (0.0) to 50 U) Trapezius (20 to 60 U) 5.9 (6.0) 6.0 (6.0) 6.0(6.0) Semispinalis (10 to 3.0 (2.0) 2.9 (2.0) 2.9 (2.0) 20 U) Spleniuscapitis (10 to 3.1 (2.0) 2.9 (2.0) 3.0 (2.0) 20 U) Note: Duringtreatment cycle 1 all patients were treated with placebo.

DISCUSSION

Chronic daily headache refers to a group of disorders characterized byhigh frequency of headaches, often associated with considerabledisability (Welch and Goadsby, 2002). Mathew et al (1987) reported that78% of CDH patients from their clinic had evolved out of a prior historyof episodic migraine. According to Holroyd et al (2000) patients withCDH report their role functioning and well-being as frequently andseverely impaired, highlighting the impact of this disease on quality oflife (Monzon and Lainez, 1998; Wang et al, 2001). There is still nosatisfactory therapeutic approach for these patients (Silvestrini et al,2003).

Pathophysiological considerations suggest that the possible basis forthe shift from episodic to chronic headache can be progressive changesin the activity of central nociceptive system (Hering et al, 1993).BOTOX® has been shown to have antinociceptive effects (Cui, 2004). Thisobservation could explain its efficacy in the treatment of migraine thathas been reported in the literature (Binder, et al, 2000; Klapper et al,2000; Mathew et al, 2003; Mauskop, 1999; Ondo et al, 2004). This studyexplored the potential benefit of BOTOX® treatment in the CDHpopulation. A modified follow-the-pain treatment paradigm was used inthis study. All patients received at least 105 U, the minimum dose,every 3 months for up to 3 treatment cycles. This minimum dose requiredinjection into six specific muscles (bilateral when appropriate) with aminimum dose per muscle specified in the protocol. Investigators wereallowed to individualize the treatment for each patient based on thelocation and severity of their headache pain. The maximum dose allowedinto 7 specified muscles was 260 U (for a maximum total exposure of 780U over the 3 treatment cycles). The protocol specified the maximum doseper muscle and a maximum imbalance for bilateral muscle treatment. Inthis study the average total dose received was 190 U.

Significant and consistent efficacy favoring BOTOX® over placebo wasobserved for the change from baseline in the frequency of headaches per30-day period. These changes were observed in the placebo non-responderand the placebo responder strata, the pooled data, and in the subgroupof patients with no baseline headache prophylactic treatment. Change inthe frequency of headache is a preferred primary endpoint in migrainetrials (European Agency for the Evaluation of Medicinal Products, 2003).Recent US FDA approved prophylactic treatment for migraine headache alsoestablished efficacy by measuring a change in frequency of headaches(Depakote package insert, 2003).

Based on the data for headache frequency, BOTOX® demonstrated an initialonset of action within 30 days of the first active treatment. Theresponse at Day 180 in those patients who completed 2 or 3 injectioncycles was similar and ranged from −7.1 to −8.0 headaches in the BOTOX®group (baseline=14) and −3.7 to −5.4 headaches in the placebo group(baseline=13) (p<0.042 from Day 180 through Day 270). A majority ofheadaches experienced by patients in this study were greater than 4hours in duration. In addition to showing that BOTOX® treatment resultedin a clinically and statistically significant decrease of all headaches,regardless of duration, there was a clinically and statisticallysignificant difference (favoring BOTOX®) in the change in the frequencyof headaches ≧4 hours in duration. The response at Day 180 in thosepatients with headaches of ≧4 hours duration was −4.6 headaches in theBOTOX® group versus −2.2 in the placebo group (baseline=9.6 and 9.2,respectively; p=0.005). In patients with headaches <4 hours, there was adecrease of −2.5 headaches in the BOTOX® group and −1.6 headaches in theplacebo group (baseline=3.9 and 3.5, respectively). This demonstratesthat BOTOX® treatment reduced the number of headaches of substantialclinical burden.

The incidence of patients experiencing a decrease in the frequency ofheadaches per 30-day period provides information on the effectiveness ofBOTOX® as a headache prophylaxis treatment for the target population.Although not a requirement for entry, all of the patients in this studyhad a migraine headache during the baseline period (ICHD level 1),supporting the underlying primary headache diagnosis of migraine and nottension-type headache. Therefore, the actual population studied wasmigraine patients with CDH.

Significant differences were found between the groups favoring BOTOX® inthe percentage of patients with a decrease from baseline of at least 50%or more per 30-day period in the number of headaches at Day 180 (54.2%vs 38.0%, p=0.046) and Day 210 (57.1% vs 36.4%, p=0.012). In addition,the percentage of patients with a 50% decrease in headaches per 30-dayperiod occurred in more than 50% of patients at Days 150, 180, 210, 240,and 270 in the BOTOX® group, while this level was reached only at Day270 in the placebo group.

The population of patients who were not using a prophylactic headachemedication at baseline was a subgroup responding to treatment withBOTOX®. Statistically significant between-group differences wereobserved for efficacy favoring BOTOX® for the mean change from baselinein the frequency of headaches as well as other efficacy variables suchas: 50% reduction from baseline in the frequency of headaches per 30-dayperiod, 30% reduction from baseline in the frequency of headaches per30-day period, number of headache days, and number of uses and days ofuse of acute analgesic headache medication per 30-day period.

Frequent use of analgesic medications is an important factor to considerin the CDH population since patients with CDH may be overusing acuteanalgesic medications (Colas et al, 2004). Currently the definition of“analgesic medication overuse” is under discussion by theheadache-research community (Bigal et al, 2002; Silberstein et al,1994), and the Headache Classification Subcommittee of the InternationalHeadache Society (Silberstein [chair of the subcommittee for definingthe IHS criteria for medication overuse] verbal communication, June,2004). The most recently proposed definition under consideration is anyuse of ≧15 days and ≧2 days per week (Silberstein verbal communication,2004).

In this study, patients were to be excluded if, in the investigator'sopinion, the patient was overusing an analgesic medication. Toinvestigate the ≧15 days and ≧2 days per week definition post hoc inthis population, patients were stratified into 2 groups: “yes” (patientis an analgesic medication overuser) or “no” (patient is not ananalgesic medication overuser). A total of 52.6% (91/173) of BOTOX®patients and 42.3% (77/182) of placebo patients in this study met thiscriterion for analgesic medication overuse at baseline. The meandecreases from baseline in the frequency of headaches per 30-day periodin the “yes” analgesic medication overuse subgroup were significantlygreater for BOTOX® than for placebo by 2.0 to 5.6 headaches at all timepoints, except for Day 90.

Frequent analgesic use has been suggested as a cause for CDH(Linton-Dahlöf et al, 2000). However, some have suggested that frequentanalgesic use may simply follow the increasing frequency of headache(Lipton and Bigal, 2003). Regardless, analgesic medication overuse is acondition that greatly decreases patients' quality of life and addssignificant socioeconomic burden to their care (Colas et al, 2004; Bigalet al, 2002; Schwartz et al, 1997). BOTOX® as a preventative agent forpatients with migraine and CDH may prove to be important in reducing thefrequency of headaches, as well as reducing analgesic medication use,and possibly analgesic medication overuse.

This study demonstrated that BOTOX® is effective and well tolerated inmigraine patients with CDH, and offers an alternative to otherprophylactic therapies in which the high incidence and severity ofadverse events affects patient compliance.

The secondary endpoint of incidence of patients with 50% or moredecrease in frequency of headache days was achieved at Day 180 in theplacebo non-responder group. In all efficacy analyses, there was astrong response to treatment with BOTOX®. A priori and post hoc analysesidentified several patient populations for whom treatment with BOTOX®showed statistically significant differences over placebo. Statisticallysignificant findings at multiple timepoints for multiple efficacyparameters were found in the subgroup of patients not taking a headacheprophylaxis at baseline. With regard to endpoints, the frequency ofheadaches per 30-day period best demonstrated BOTOX® effectiveness overplacebo. Additionally, there was a significantly greater decrease in theuse and days of use of acute analgesic headache medications for patientstreated with BOTOX® compared to those treated with placebo, particularlyin the subgroup of patients not taking a headache prophylaxis atbaseline. BOTOX® was also shown to be safe and well tolerated in thismodified follow-the-pain regimen, when administered every 3 months indoses up to 260 U per treatment cycle.

A botulinum toxin type B, C, D, E, F or G can be substituted for thebotulinum toxin type A used above, for example by use of about 10,000units of a botulinum toxin type B, that is by use of about fifty timesthe amount of the botulinum toxin type A used in the study set forth inExample 1.

Although the present invention has been described in detail with regardto certain preferred methods, other embodiments, versions, andmodifications within the scope of the present invention are possible.For example, a wide variety of neurotoxins can be effectively used inthe methods of the present invention. Additionally, the presentinvention includes local administration methods to alleviate a headachepain or to reduce the number of headaches wherein two or moreneurotoxins, such as two or more botulinum toxins, are administeredconcurrently or consecutively. For example, botulinum toxin type A canbe administered until a loss of clinical response or neutralizingantibodies develop, followed by administration of botulinum toxin typeB. Alternately, a combination of any two or more of the botulinumserotypes A-G can be locally administered to control the onset andduration of the desired therapeutic result. Furthermore, non-neurotoxincompounds can be administered prior to, concurrently with or subsequentto administration of the neurotoxin to proved adjunct effect such asenhanced or a more rapid onset of denervation before the neurotoxin,such as a botulinum toxin, begins to exert its therapeutic effect.

A method for treating a disorder according to the invention disclosedherein has many benefits and advantages, including the following:

1. Headaches can be eliminated.

2. symptoms of pain, such as a headache pain can be dramatically reducedor eliminated.

3. the symptoms of a pain can be reduced or eliminated for at leastabout two to about six months per injection of neurotoxin and for fromabout one year to about five years upon use of a controlled releaseneurotoxin implant.

4. headaches can be eliminated for at least about two to about sixmonths per injection of neurotoxin and for from about one year to aboutfive years.

5. a medication overuse disorder, such as MOH, can be effectivelytreated.

6. the efficacy of a triptan medication can be increased.

Although the present invention has been described in detail with regardto certain preferred methods, other embodiments, versions, andmodifications within the scope of the present invention are possible.For example, a wide variety of neurotoxins can be effectively used inthe methods of the present invention. Additionally, the presentinvention includes local administration methods wherein two or moreClostridial neurotoxins, such as two or more botulinum toxins, areadministered concurrently or consecutively. For example, botulinum toxintype A can be locally administered until a loss of clinical response orneutralizing antibodies develop, followed by administration of botulinumtoxin type B. Furthermore, non-neurotoxin compounds can be locallyadministered prior to, concurrently with or subsequent to administrationof the neurotoxin to provide adjunct effect such as enhanced or a morerapid onset of pain suppression before the neurotoxin, such as abotulinum toxin, begins to exert its more long lasting pain and MOHsuppressant effect.

Our invention also includes within its scope the use of a neurotoxin,such as a botulinum neurotoxin, in the preparation of a medicament forthe treatment of a medication overuse disorder, by local administrationof the botulinum toxin.

All references, articles, patents, applications and publications setforth above are incorporated herein by reference in their entireties.

Accordingly, the spirit and scope of the following claims should not belimited to the descriptions of the preferred embodiments set forthabove.

We claim:
 1. A method for reducing the occurrence of or alleviating aheadache in a patient with tension-type headaches, the method comprisinglocal administration by injection of a composition comprising abotulinum toxin type A, wherein the number of injection sites is 23 to58, the number of muscle areas injected is 6 to 7 and the botulinumtoxin type A dose is 105 to 260 units, and wherein at least thefrontal/glabellar, occipitalis, temporalis, semispinalis, spleniuscapitis or trapezius muscles are injected.
 2. The method of claim 1,wherein the administration is subdermal or subcutaneous.